Fix how the default.prop modifications from the UI are reloaded.

The UI to edit the target and library changed the ProjectState
directly, causing havoc on the filelistener which *must* be the
entry point to reload modification into ProjectState.

This patch makes the UI work on a copy of the properties which
are then saved separately from the ProjectState (whose save()
method disappeared).

A next patch will enforce the ProjectProperties of the ProjectState
to be read only so that this does not happen again (forcing
to clone it before modifying/saving it).

This patch also fixes the reloading/relinking of the libraries upon
modification of the default.prop but more work is needed here.

Change-Id: Ie6a23111242005eb91b7533b506c029ba602f0f3

9 files changed, 478 insertions, 351 deletions

diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/project/ProjectState.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/project/ProjectState.java
index 5886692..d5cddc1 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/project/ProjectState.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/project/ProjectState.java
@@ -19,15 +19,12 @@ package com.android.ide.eclipse.adt.internal.project;
 import com.android.ide.eclipse.adt.AdtPlugin;
 import com.android.ide.eclipse.adt.internal.sdk.Sdk;
 import com.android.sdklib.IAndroidTarget;
-import com.android.sdklib.SdkConstants;
 import com.android.sdklib.internal.project.ApkSettings;
 import com.android.sdklib.internal.project.ProjectProperties;
+import com.android.sdklib.internal.project.ProjectPropertiesWorkingCopy;
 
 import org.eclipse.core.resources.IProject;
-import org.eclipse.core.resources.IResource;
-import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
-import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Status;
 
 import java.io.File;
@@ -177,6 +174,10 @@ public final class ProjectState {
     private final ArrayList<ProjectState> mParentProjects = new ArrayList<ProjectState>();
 
     public ProjectState(IProject project, ProjectProperties properties) {
+        if (project == null || properties == null) {
+            throw new NullPointerException();
+        }
+
         mProject = project;
         mProperties = properties;
 
@@ -224,11 +225,7 @@ public final class ProjectState {
             return mTarget.hashString();
         }
 
-        if (mProperties != null) {
-            return mProperties.getProperty(ProjectProperties.PROPERTY_TARGET);
-        }
-
-        return null;
+        return mProperties.getProperty(ProjectProperties.PROPERTY_TARGET);
     }
 
     public IAndroidTarget getTarget() {
@@ -552,29 +549,15 @@ public final class ProjectState {
     }
 
     /**
-     * Saves the default.properties file and refreshes it to make sure that it gets reloaded
-     * by Eclipse
-     * @throws Exception
+     * Update the value of a library dependency.
+     * <p/>This loops on all current dependency looking for the value to replace and then replaces
+     * it.
+     * <p/>This both updates the in-memory {@link #mProperties} values and on-disk
+     * default.properties file.
+     * @param oldValue the old value to replace
+     * @param newValue the new value to set.
+     * @return the status of the replacement. If null, no replacement was done (value not found).
      */
-    public void saveProperties() throws CoreException {
-        try {
-            mProperties.save();
-
-            IResource defaultProp = mProject.findMember(SdkConstants.FN_DEFAULT_PROPERTIES);
-            defaultProp.refreshLocal(IResource.DEPTH_ZERO, new NullProgressMonitor());
-        } catch (Exception e) {
-            String msg = String.format(
-                    "Failed to save %1$s for project %2$s",
-                    SdkConstants.FN_DEFAULT_PROPERTIES, mProject.getName());
-            AdtPlugin.log(e, msg);
-            if (e instanceof CoreException) {
-                throw (CoreException)e;
-            } else {
-                throw new CoreException(new Status(IStatus.ERROR, AdtPlugin.PLUGIN_ID, msg, e));
-            }
-        }
-    }
-
     private IStatus replaceLibraryProperty(String oldValue, String newValue) {
         int index = 1;
         while (true) {
@@ -586,9 +569,15 @@ public final class ProjectState {
             }
 
             if (rootPath.equals(oldValue)) {
-                mProperties.setProperty(propName, newValue);
+                // need to update the properties. Get a working copy to change it and save it on
+                // disk since ProjectProperties is read-only.
+                ProjectPropertiesWorkingCopy workingCopy = mProperties.makeWorkingCopy();
+                workingCopy.setProperty(propName, newValue);
                 try {
-                    mProperties.save();
+                    workingCopy.save();
+
+                    // reload the properties with the new values from the disk.
+                    mProperties.reload();
                 } catch (Exception e) {
                     return new Status(IStatus.ERROR, AdtPlugin.PLUGIN_ID, String.format(
                             "Failed to save %1$s for project %2$s",
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/AndroidPropertyPage.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/AndroidPropertyPage.java
index 44da3a9..ba69977 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/AndroidPropertyPage.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/AndroidPropertyPage.java
@@ -16,14 +16,18 @@
 
 package com.android.ide.eclipse.adt.internal.properties;
 
+import com.android.ide.eclipse.adt.AdtPlugin;
 import com.android.ide.eclipse.adt.internal.project.ProjectState;
 import com.android.ide.eclipse.adt.internal.sdk.Sdk;
 import com.android.sdklib.IAndroidTarget;
+import com.android.sdklib.SdkConstants;
 import com.android.sdklib.internal.project.ProjectProperties;
+import com.android.sdklib.internal.project.ProjectPropertiesWorkingCopy;
 import com.android.sdkuilib.internal.widgets.SdkTargetSelector;
 
 import org.eclipse.core.resources.IProject;
-import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.SelectionAdapter;
 import org.eclipse.swt.events.SelectionEvent;
@@ -50,6 +54,7 @@ public class AndroidPropertyPage extends PropertyPage implements IWorkbenchPrope
     // APK-SPLIT: This is not yet supported, so we hide the UI
 //    private Button mSplitByDensity;
     private LibraryProperties mLibraryDependencies;
+    private ProjectPropertiesWorkingCopy mPropertiesWorkingCopy;
 
     public AndroidPropertyPage() {
         // pass
@@ -123,22 +128,20 @@ public class AndroidPropertyPage extends PropertyPage implements IWorkbenchPrope
         if (currentSdk != null && mProject.isOpen()) {
             ProjectState state = Sdk.getProjectState(mProject);
 
-            // simply update the project properties. Eclipse will be notified of the file change
+            // simply update the properties copy. Eclipse will be notified of the file change
             // and will reload it smartly (detecting differences) and updating the ProjectState.
             // See Sdk.mFileListener
-            ProjectProperties properties = null;
             boolean mustSaveProp = false;
 
             IAndroidTarget newTarget = mSelector.getSelected();
             if (newTarget != state.getTarget()) {
-                properties = state.getProperties();
-                properties.setProperty(ProjectProperties.PROPERTY_TARGET, newTarget.hashString());
+                mPropertiesWorkingCopy.setProperty(ProjectProperties.PROPERTY_TARGET,
+                        newTarget.hashString());
                 mustSaveProp = true;
             }
 
             if (mIsLibrary.getSelection() != state.isLibrary()) {
-                properties = state.getProperties();
-                properties.setProperty(ProjectProperties.PROPERTY_LIBRARY,
+                mPropertiesWorkingCopy.setProperty(ProjectProperties.PROPERTY_LIBRARY,
                         Boolean.toString(mIsLibrary.getSelection()));
                 mustSaveProp = true;
             }
@@ -151,9 +154,15 @@ public class AndroidPropertyPage extends PropertyPage implements IWorkbenchPrope
 
             if (mustSaveProp) {
                 try {
-                    state.saveProperties();
-                } catch (CoreException e) {
-                    // pass
+                    mPropertiesWorkingCopy.save();
+
+                    IResource defaultProp = mProject.findMember(SdkConstants.FN_DEFAULT_PROPERTIES);
+                    defaultProp.refreshLocal(IResource.DEPTH_ZERO, new NullProgressMonitor());
+                } catch (Exception e) {
+                    String msg = String.format(
+                            "Failed to save %1$s for project %2$s",
+                            SdkConstants.FN_DEFAULT_PROPERTIES, mProject.getName());
+                    AdtPlugin.log(e, msg);
                 }
             }
         }
@@ -171,6 +180,9 @@ public class AndroidPropertyPage extends PropertyPage implements IWorkbenchPrope
         if (Sdk.getCurrent() != null && mProject.isOpen()) {
             ProjectState state = Sdk.getProjectState(mProject);
 
+            // make a working copy of the properties
+            mPropertiesWorkingCopy = state.getProperties().makeWorkingCopy();
+
             // get the target
             IAndroidTarget target = state.getTarget();;
             if (target != null) {
@@ -178,7 +190,7 @@ public class AndroidPropertyPage extends PropertyPage implements IWorkbenchPrope
             }
 
             mIsLibrary.setSelection(state.isLibrary());
-            mLibraryDependencies.setContent(state);
+            mLibraryDependencies.setContent(state, mPropertiesWorkingCopy);
 
             /*
              * APK-SPLIT: This is not yet supported, so we hide the UI
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/LibraryProperties.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/LibraryProperties.java
index 67de298..1f5f2c6 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/LibraryProperties.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/properties/LibraryProperties.java
@@ -23,6 +23,7 @@ import com.android.ide.eclipse.adt.internal.project.ProjectChooserHelper.IProjec
 import com.android.ide.eclipse.adt.internal.project.ProjectState.LibraryState;
 import com.android.ide.eclipse.adt.internal.sdk.Sdk;
 import com.android.sdklib.internal.project.ProjectProperties;
+import com.android.sdklib.internal.project.ProjectPropertiesWorkingCopy;
 
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.IPath;
@@ -65,7 +66,16 @@ final class LibraryProperties {
     private Button mDownButton;
     private ProjectChooserHelper mProjectChooser;
 
+    /**
+     * Original ProjectState being edited. This is read-only.
+     * @see #mPropertiesWorkingCopy
+     */
     private ProjectState mState;
+    /**
+     * read-write copy of the properties being edited.
+     */
+    private ProjectPropertiesWorkingCopy mPropertiesWorkingCopy;
+
     private final List<ItemData> mItemDataList = new ArrayList<ItemData>();
     private boolean mMustSave = false;
 
@@ -231,10 +241,12 @@ final class LibraryProperties {
 
     /**
      * Sets or reset the content.
-     * @param state the {@link ProjectState} to display
+     * @param state the {@link ProjectState} to display. This is read-only.
+     * @param propertiesWorkingCopy the working copy of {@link ProjectProperties} to modify.
      */
-    void setContent(ProjectState state) {
+    void setContent(ProjectState state, ProjectPropertiesWorkingCopy propertiesWorkingCopy) {
         mState = state;
+        mPropertiesWorkingCopy = propertiesWorkingCopy;
 
         // reset content
         mTable.removeAll();
@@ -254,10 +266,12 @@ final class LibraryProperties {
     }
 
     /**
-     * Saves the state of the UI into the {@link ProjectState} object that was given to
+     * Saves the state of the UI into the {@link ProjectProperties} object that was returned by
      * {@link #setContent(ProjectState)}.
-     * <p/>This only saves the data into the {@link ProjectProperties} of the state, but does
-     * not update the {@link ProjectState} or the list of {@link LibraryState}.
+     * <p/>This does not update the {@link ProjectState} object that was provided, nor does it save
+     * the new properties on disk. Saving the properties on disk, via
+     * {@link ProjectProperties#save()}, and updating the {@link ProjectState} instance, via
+     * {@link ProjectState#reloadProperties()} must be done by the caller.
      * @return <code>true</code> if there was actually new data saved in the project state, false
      * otherwise.
      */
@@ -265,18 +279,17 @@ final class LibraryProperties {
         boolean mustSave = mMustSave;
         if (mMustSave) {
             // remove all previous library dependencies.
-            ProjectProperties props = mState.getProperties();
-            Set<String> keys = props.keySet();
+            Set<String> keys = mPropertiesWorkingCopy.keySet();
             for (String key : keys) {
                 if (key.startsWith(ProjectProperties.PROPERTY_LIB_REF)) {
-                    props.removeProperty(key);
+                    mPropertiesWorkingCopy.removeProperty(key);
                 }
             }
 
             // now add the new libraries.
             int index = 1;
             for (ItemData data : mItemDataList) {
-                props.setProperty(ProjectProperties.PROPERTY_LIB_REF + index++,
+                mPropertiesWorkingCopy.setProperty(ProjectProperties.PROPERTY_LIB_REF + index++,
                         data.relativePath);
             }
         }
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/sdk/Sdk.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/sdk/Sdk.java
index 9423ae7..9db385a 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/sdk/Sdk.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/sdk/Sdk.java
@@ -37,6 +37,7 @@ import com.android.sdklib.SdkConstants;
 import com.android.sdklib.SdkManager;
 import com.android.sdklib.internal.avd.AvdManager;
 import com.android.sdklib.internal.project.ProjectProperties;
+import com.android.sdklib.internal.project.ProjectPropertiesWorkingCopy;
 import com.android.sdklib.internal.project.ProjectProperties.PropertyType;
 import com.android.sdklib.io.StreamException;
 
@@ -306,10 +307,10 @@ public final class Sdk  {
             // check if there's already a state?
             ProjectState state = getProjectState(project);
 
-            ProjectProperties properties = null;
+            ProjectPropertiesWorkingCopy properties = null;
 
             if (state != null) {
-                properties = state.getProperties();
+                properties = state.getProperties().makeWorkingCopy();
             }
 
             if (properties == null) {
@@ -890,82 +891,88 @@ public final class Sdk  {
         public void fileChanged(final IFile file, IMarkerDelta[] markerDeltas, int kind) {
             if (SdkConstants.FN_DEFAULT_PROPERTIES.equals(file.getName()) &&
                     file.getParent() == file.getProject()) {
-                // we can't do the change from the Workspace resource change notification
-                // so we create build-type job for it.
-                Job job = new Job("Project Update") {
-                    @Override
-                    protected IStatus run(IProgressMonitor monitor) {
-                        try {
-                            // reload the content of the default.properties file and update
-                            // the target.
-                            IProject iProject = file.getProject();
-                            ProjectState state = Sdk.getProjectState(iProject);
-
-                            // get the current target
-                            IAndroidTarget oldTarget = state.getTarget();
-
-                            LibraryDifference diff = state.reloadProperties();
-
-                            // load the (possibly new) target.
-                            IAndroidTarget newTarget = loadTarget(state);
-
-                            // reload the libraries if needed
-                            if (diff.hasDiff()) {
-                                for (LibraryState removedState : diff.removed) {
-                                    ProjectState removedPState = removedState.getProjectState();
-                                    if (removedPState != null) {
-                                        startActionBundle(
-                                                new UnlinkLibraryBundle(
-                                                        state, removedPState.getProject()));
-                                    }
-                                }
+                try {
+                    // reload the content of the default.properties file and update
+                    // the target.
+                    IProject iProject = file.getProject();
+                    ProjectState state = Sdk.getProjectState(iProject);
+
+                    // get the current target
+                    IAndroidTarget oldTarget = state.getTarget();
+
+                    // get the current library flag
+                    boolean wasLibrary = state.isLibrary();
 
-                                if (diff.added) {
-                                    synchronized (sLock) {
-                                        for (ProjectState projectState : sProjectStateMap.values()) {
-                                            if (projectState != state) {
-                                                LibraryState libState = state.needs(projectState);
-
-                                                if (libState != null) {
-                                                    IProject[] libArray = new IProject[] {
-                                                            libState.getProjectState().getProject()
-                                                    };
-                                                    LinkLibraryBundle bundle =
-                                                            new LinkLibraryBundle();
-                                                    bundle.mProject = iProject;
-                                                    bundle.mLibraryProjects = libArray;
-                                                    bundle.mPreviousLibraryPath = null;
-                                                    bundle.mCleanupCPE = false;
-                                                    startActionBundle(bundle);
-                                                }
+                    LibraryDifference diff = state.reloadProperties();
+
+                    // load the (possibly new) target.
+                    IAndroidTarget newTarget = loadTarget(state);
+
+                    // check if this is a new library
+                    if (state.isLibrary() && wasLibrary == false) {
+                        setupLibraryProject(iProject);
+                    }
+
+                    // reload the libraries if needed
+                    if (diff.hasDiff()) {
+                        for (LibraryState removedState : diff.removed) {
+                            ProjectState removedPState = removedState.getProjectState();
+                            if (removedPState != null) {
+                                startActionBundle(
+                                        new UnlinkLibraryBundle(
+                                                state, removedPState.getProject()));
+                            }
+                        }
+
+                        if (diff.added) {
+                            ArrayList<IProject> libsToLink = new ArrayList<IProject>();
+                            synchronized (sLock) {
+                                for (ProjectState projectState : sProjectStateMap.values()) {
+                                    if (projectState != state) {
+                                        LibraryState libState = state.needs(projectState);
+
+                                        if (libState != null) {
+                                            IProject p = libState.getProjectState().getProject();
+                                            if (libsToLink.contains(p) == false) {
+                                                libsToLink.add(p);
                                             }
+
+                                            // now find the dependencies of the library itself.
+                                            fillProjectDependenciesList(
+                                                    libState.getMainProjectState(), libsToLink);
                                         }
                                     }
                                 }
                             }
 
-                            // apply the new target if needed.
-                            if (newTarget != oldTarget) {
-                                IJavaProject javaProject = BaseProjectHelper.getJavaProject(
-                                        file.getProject());
-                                if (javaProject != null) {
-                                    AndroidClasspathContainerInitializer.updateProjects(
-                                            new IJavaProject[] { javaProject });
-                                }
-
-                                // update the editors to reload with the new target
-                                AdtPlugin.getDefault().updateTargetListeners(iProject);
+                            if (libsToLink.size() > 0) {
+                                LinkLibraryBundle bundle = new LinkLibraryBundle();
+                                bundle.mProject = iProject;
+                                bundle.mLibraryProjects =
+                                        libsToLink.toArray(new IProject[libsToLink.size()]);
+                                bundle.mPreviousLibraryPath = null;
+                                bundle.mCleanupCPE = false;
+                                startActionBundle(bundle);
                             }
-                        } catch (CoreException e) {
-                            // This can't happen as it's only for closed project (or non existing)
-                            // but in that case we can't get a fileChanged on this file.
                         }
+                    }
 
-                        return Status.OK_STATUS;
+                    // apply the new target if needed.
+                    if (newTarget != oldTarget) {
+                        IJavaProject javaProject = BaseProjectHelper.getJavaProject(
+                                file.getProject());
+                        if (javaProject != null) {
+                            AndroidClasspathContainerInitializer.updateProjects(
+                                    new IJavaProject[] { javaProject });
+                        }
+
+                        // update the editors to reload with the new target
+                        AdtPlugin.getDefault().updateTargetListeners(iProject);
                     }
-                };
-                job.setPriority(Job.BUILD); // build jobs are run after other interactive jobs
-                job.schedule();
+                } catch (CoreException e) {
+                    // This can't happen as it's only for closed project (or non existing)
+                    // but in that case we can't get a fileChanged on this file.
+                }
             }
         }
     };
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/wizards/newproject/NewProjectCreationPage.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/wizards/newproject/NewProjectCreationPage.java
index bd50e16..d17e3cf 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/wizards/newproject/NewProjectCreationPage.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/wizards/newproject/NewProjectCreationPage.java
@@ -31,6 +31,7 @@ import com.android.ide.eclipse.adt.internal.wizards.newproject.NewTestProjectCre
 import com.android.sdklib.IAndroidTarget;
 import com.android.sdklib.SdkConstants;
 import com.android.sdklib.internal.project.ProjectProperties;
+import com.android.sdklib.internal.project.ProjectPropertiesWorkingCopy;
 import com.android.sdklib.internal.project.ProjectProperties.PropertyType;
 import com.android.sdklib.xml.AndroidManifest;
 import com.android.sdklib.xml.ManifestData;
@@ -1096,7 +1097,7 @@ public class NewProjectCreationPage extends WizardPage {
         // is tied to the current target, so changing it would invalidate the project we're
         // trying to load in the first place.
         if (currentTarget == null || !mInfo.isCreateFromSample()) {
-            ProjectProperties p = ProjectProperties.create(projectLocation, null);
+            ProjectPropertiesWorkingCopy p = ProjectProperties.create(projectLocation, null);
             if (p != null) {
                 // Check the {build|default}.properties files if present
                 p.merge(PropertyType.BUILD).merge(PropertyType.DEFAULT);
diff --git a/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ApkSettings.java b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ApkSettings.java
index 3b8e85c..511b4ef 100644
--- a/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ApkSettings.java
+++ b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ApkSettings.java
@@ -64,18 +64,18 @@ public class ApkSettings {
     }
 
     public boolean isSplitByAbi() {
-    	return mSplitByAbi;
+        return mSplitByAbi;
     }
 
     public void setSplitByAbi(boolean split) {
-    	mSplitByAbi = split;
+        mSplitByAbi = split;
     }
 
     /**
-     * Writes the receiver into a {@link ProjectProperties}.
-     * @param properties the {@link ProjectProperties} in which to store the settings.
+     * Writes the receiver into a {@link ProjectPropertiesWorkingCopy}.
+     * @param properties the {@link ProjectPropertiesWorkingCopy} in which to store the settings.
      */
-    public void write(ProjectProperties properties) {
+    public void write(ProjectPropertiesWorkingCopy properties) {
         properties.setProperty(ProjectProperties.PROPERTY_SPLIT_BY_DENSITY,
                 Boolean.toString(mSplitByDensity));
         properties.setProperty(ProjectProperties.PROPERTY_SPLIT_BY_ABI,
diff --git a/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectCreator.java b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectCreator.java
index 4eda46c..df58290 100644
--- a/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectCreator.java
+++ b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectCreator.java
@@ -21,7 +21,6 @@ import com.android.sdklib.ISdkLog;
 import com.android.sdklib.SdkConstants;
 import com.android.sdklib.SdkManager;
 import com.android.sdklib.internal.project.ProjectProperties.PropertyType;
-import com.android.sdklib.io.StreamException;
 import com.android.sdklib.xml.AndroidManifest;
 import com.android.sdklib.xml.AndroidXPathFactory;
 
@@ -187,13 +186,13 @@ public class ProjectCreator {
             // first create the project properties.
 
             // location of the SDK goes in localProperty
-            ProjectProperties localProperties = ProjectProperties.create(folderPath,
+            ProjectPropertiesWorkingCopy localProperties = ProjectProperties.create(folderPath,
                     PropertyType.LOCAL);
             localProperties.setProperty(ProjectProperties.PROPERTY_SDK, mSdkFolder);
             localProperties.save();
 
             // target goes in default properties
-            ProjectProperties defaultProperties = ProjectProperties.create(folderPath,
+            ProjectPropertiesWorkingCopy defaultProperties = ProjectProperties.create(folderPath,
                     PropertyType.DEFAULT);
             defaultProperties.setProperty(ProjectProperties.PROPERTY_TARGET, target.hashString());
             if (library) {
@@ -202,7 +201,7 @@ public class ProjectCreator {
             defaultProperties.save();
 
             // create a build.properties file with just the application package
-            ProjectProperties buildProperties = ProjectProperties.create(folderPath,
+            ProjectPropertiesWorkingCopy buildProperties = ProjectProperties.create(folderPath,
                     PropertyType.BUILD);
 
             // only put application.package for older target where the rules file didn't.
@@ -375,13 +374,13 @@ public class ProjectCreator {
 
         try {
             // location of the SDK goes in localProperty
-            ProjectProperties localProperties = ProjectProperties.create(folderPath,
+            ProjectPropertiesWorkingCopy localProperties = ProjectProperties.create(folderPath,
                     PropertyType.LOCAL);
             localProperties.setProperty(ProjectProperties.PROPERTY_SDK, mSdkFolder);
             localProperties.save();
 
             // package name goes in export properties
-            ProjectProperties exportProperties = ProjectProperties.create(folderPath,
+            ProjectPropertiesWorkingCopy exportProperties = ProjectProperties.create(folderPath,
                     PropertyType.EXPORT);
             exportProperties.setProperty(ProjectProperties.PROPERTY_PACKAGE, packageName);
             exportProperties.setProperty(ProjectProperties.PROPERTY_VERSIONCODE, "1");
@@ -506,21 +505,28 @@ public class ProjectCreator {
 
         boolean saveDefaultProps = false;
 
+        ProjectPropertiesWorkingCopy propsWC = null;
+
         // Update default.prop if --target was specified
         if (target != null) {
             // we already attempted to load the file earlier, if that failed, create it.
             if (props == null) {
-                props = ProjectProperties.create(folderPath, PropertyType.DEFAULT);
+                propsWC = ProjectProperties.create(folderPath, PropertyType.DEFAULT);
+            } else {
+                propsWC = props.makeWorkingCopy();
             }
 
             // set or replace the target
-            props.setProperty(ProjectProperties.PROPERTY_TARGET, target.hashString());
+            propsWC.setProperty(ProjectProperties.PROPERTY_TARGET, target.hashString());
             saveDefaultProps = true;
         }
 
         if (libraryPath != null) {
             // at this point, the default properties already exists, either because they were
             // already there or because they were created with a new target
+            if (propsWC == null) {
+                propsWC = props.makeWorkingCopy();
+            }
 
             // check the reference is valid
             File libProject = new File(libraryPath);
@@ -558,14 +564,14 @@ public class ProjectCreator {
             }
 
             String propName = ProjectProperties.PROPERTY_LIB_REF + Integer.toString(index);
-            props.setProperty(propName, libraryPath);
+            propsWC.setProperty(propName, libraryPath);
             saveDefaultProps = true;
         }
 
         // save the default props if needed.
         if (saveDefaultProps) {
             try {
-                props.save();
+                propsWC.save();
                 println("Updated %1$s", PropertyType.DEFAULT.getFilename());
             } catch (Exception e) {
                 mLog.error(e, "Failed to write %1$s file in '%2$s'",
@@ -580,13 +586,15 @@ public class ProjectCreator {
         // we first try to load it.
         props = ProjectProperties.load(folderPath, PropertyType.LOCAL);
         if (props == null) {
-            props = ProjectProperties.create(folderPath, PropertyType.LOCAL);
+            propsWC = ProjectProperties.create(folderPath, PropertyType.LOCAL);
+        } else {
+            propsWC = props.makeWorkingCopy();
         }
 
         // set or replace the sdk location.
-        props.setProperty(ProjectProperties.PROPERTY_SDK, mSdkFolder);
+        propsWC.setProperty(ProjectProperties.PROPERTY_SDK, mSdkFolder);
         try {
-            props.save();
+            propsWC.save();
             println("Updated %1$s", PropertyType.LOCAL.getFilename());
         } catch (Exception e) {
             mLog.error(e, "Failed to write %1$s file in '%2$s'",
@@ -759,14 +767,17 @@ public class ProjectCreator {
 
         // add the test project specific properties.
         ProjectProperties buildProps = ProjectProperties.load(folderPath, PropertyType.BUILD);
+        ProjectPropertiesWorkingCopy buildWorkingCopy;
         if (buildProps == null) {
-            buildProps = ProjectProperties.create(folderPath, PropertyType.BUILD);
+            buildWorkingCopy = ProjectProperties.create(folderPath, PropertyType.BUILD);
+        } else {
+            buildWorkingCopy = buildProps.makeWorkingCopy();
         }
 
         // set or replace the path to the main project
-        buildProps.setProperty(ProjectProperties.PROPERTY_TESTED_PROJECT, pathToMainProject);
+        buildWorkingCopy.setProperty(ProjectProperties.PROPERTY_TESTED_PROJECT, pathToMainProject);
         try {
-            buildProps.save();
+            buildWorkingCopy.save();
             println("Updated %1$s", PropertyType.BUILD.getFilename());
         } catch (Exception e) {
             mLog.error(e, "Failed to write %1$s file in '%2$s'",
@@ -806,14 +817,17 @@ public class ProjectCreator {
         // because the file may already exist and contain other values (like apk config),
         // we first try to load it.
         ProjectProperties props = ProjectProperties.load(folderPath, PropertyType.LOCAL);
+        ProjectPropertiesWorkingCopy localPropsWorkingCopy;
         if (props == null) {
-            props = ProjectProperties.create(folderPath, PropertyType.LOCAL);
+            localPropsWorkingCopy = ProjectProperties.create(folderPath, PropertyType.LOCAL);
+        } else {
+            localPropsWorkingCopy = props.makeWorkingCopy();
         }
 
         // set or replace the sdk location.
-        props.setProperty(ProjectProperties.PROPERTY_SDK, mSdkFolder);
+        localPropsWorkingCopy.setProperty(ProjectProperties.PROPERTY_SDK, mSdkFolder);
         try {
-            props.save();
+            localPropsWorkingCopy.save();
             println("Updated %1$s", PropertyType.LOCAL.getFilename());
         } catch (Exception e) {
             mLog.error(e, "Failed to write %1$s file in '%2$s'",
diff --git a/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectProperties.java b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectProperties.java
index 40b055a..4aea001 100644
--- a/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectProperties.java
+++ b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectProperties.java
@@ -25,29 +25,34 @@ import com.android.sdklib.io.IAbstractFolder;
 import com.android.sdklib.io.StreamException;
 
 import java.io.BufferedReader;
-import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.io.OutputStream;
-import java.io.OutputStreamWriter;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
-import java.util.Map.Entry;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 /**
- * Class to load and save project properties for both ADT and Ant-based build.
+ * Class representing project properties for both ADT and Ant-based build.
+ * <p/>The class is associated to a {@link PropertyType} that indicate which of the project
+ * property file is represented.
+ * <p/>To load an existing file, use {@link #load(IAbstractFolder, PropertyType)}.
+ * <p/>The class is meant to be always in sync (or at least not newer) than the file it represents.
+ * Once created, it can only be updated through {@link #reload()}
+ *
+ * <p/>The make modification or make new file, use a {@link ProjectPropertiesWorkingCopy} instance,
+ * either through {@link #create(IAbstractFolder, PropertyType)} or through
+ * {@link #makeWorkingCopy()}.
  *
  */
-public final class ProjectProperties {
-    private final static Pattern PATTERN_PROP = Pattern.compile(
+public class ProjectProperties {
+    protected final static Pattern PATTERN_PROP = Pattern.compile(
     "^([a-zA-Z0-9._-]+)\\s*=\\s*(.*)\\s*$");
 
     /** The property name for the project target */
@@ -55,6 +60,7 @@ public final class ProjectProperties {
 
     public final static String PROPERTY_LIBRARY = "android.library";
     public final static String PROPERTY_LIB_REF = "android.library.reference.";
+    private final static String PROPERTY_LIB_REF_REGEX = "android.library.reference.\\d+";
 
     public final static String PROPERTY_SDK = "sdk.dir";
     // LEGACY - compatibility with 1.6 and before
@@ -83,7 +89,7 @@ public final class ProjectProperties {
                 PROPERTY_BUILD_SOURCE_DIR, PROPERTY_BUILD_OUT_DIR
             }),
         DEFAULT(SdkConstants.FN_DEFAULT_PROPERTIES, DEFAULT_HEADER, new String[] {
-                PROPERTY_TARGET, PROPERTY_LIBRARY, PROPERTY_LIB_REF,
+                PROPERTY_TARGET, PROPERTY_LIBRARY, PROPERTY_LIB_REF_REGEX,
                 PROPERTY_KEY_STORE, PROPERTY_KEY_ALIAS
             }),
         LOCAL(SdkConstants.FN_LOCAL_PROPERTIES, LOCAL_HEADER, new String[] {
@@ -96,26 +102,35 @@ public final class ProjectProperties {
 
         private final String mFilename;
         private final String mHeader;
-        private final Set<String> mValidProps;
+        private final Set<String> mKnownProps;
 
         PropertyType(String filename, String header, String[] validProps) {
             mFilename = filename;
             mHeader = header;
             HashSet<String> s = new HashSet<String>();
             s.addAll(Arrays.asList(validProps));
-            mValidProps = Collections.unmodifiableSet(s);
+            mKnownProps = Collections.unmodifiableSet(s);
         }
 
         public String getFilename() {
             return mFilename;
         }
 
+        public String getHeader() {
+            return mHeader;
+        }
+
         /**
-         * Returns an unmodifyable {@link Set} of the known properties for that type of
-         * property file.
+         * Returns whether a given property is known for the property type.
          */
-        public Set<String> getValidProps() {
-            return mValidProps;
+        public boolean isKnownProperty(String name) {
+            for (String propRegex : mKnownProps) {
+                if (propRegex.equals(name) || Pattern.matches(propRegex, name)) {
+                    return true;
+                }
+            }
+
+            return false;
         }
     }
 
@@ -178,33 +193,9 @@ public final class ProjectProperties {
            "# The password will be asked during the build when you use the 'release' target.\n" +
            "\n";
 
-    private final static Map<String, String> COMMENT_MAP = new HashMap<String, String>();
-    static {
-//               1-------10--------20--------30--------40--------50--------60--------70--------80
-        COMMENT_MAP.put(PROPERTY_TARGET,
-                "# Project target.\n");
-        COMMENT_MAP.put(PROPERTY_SPLIT_BY_DENSITY,
-                "# Indicates whether an apk should be generated for each density.\n");
-        COMMENT_MAP.put(PROPERTY_SDK,
-                "# location of the SDK. This is only used by Ant\n" +
-                "# For customization when using a Version Control System, please read the\n" +
-                "# header note.\n");
-        COMMENT_MAP.put(PROPERTY_APP_PACKAGE,
-                "# The name of your application package as defined in the manifest.\n" +
-                "# Used by the 'uninstall' rule.\n");
-        COMMENT_MAP.put(PROPERTY_PACKAGE,
-                "# Package of the application being exported\n");
-        COMMENT_MAP.put(PROPERTY_VERSIONCODE,
-                "# Major version code\n");
-        COMMENT_MAP.put(PROPERTY_PROJECTS,
-                "# List of the Android projects being used for the export.\n" +
-                "# The list is made of paths that are relative to this project,\n" +
-                "# using forward-slash (/) as separator, and are separated by colons (:).\n");
-    }
-
-    private final IAbstractFolder mProjectFolder;
-    private final Map<String, String> mProperties;
-    private final PropertyType mType;
+    protected final IAbstractFolder mProjectFolder;
+    protected final Map<String, String> mProperties;
+    protected final PropertyType mType;
 
     /**
      * Loads a project properties file and return a {@link ProjectProperties} object
@@ -239,48 +230,13 @@ public final class ProjectProperties {
     }
 
     /**
-     * Merges all properties from the given file into the current properties.
-     * <p/>
-     * This emulates the Ant behavior: existing properties are <em>not</em> overriden.
-     * Only new undefined properties become defined.
-     * <p/>
-     * Typical usage:
-     * <ul>
-     * <li>Create a ProjectProperties with {@link PropertyType#BUILD}
-     * <li>Merge in values using {@link PropertyType#DEFAULT}
-     * <li>The result is that this contains all the properties from default plus those
-     *     overridden by the build.properties file.
-     * </ul>
-     *
-     * @param type One the possible {@link PropertyType}s.
-     * @return this object, for chaining.
-     */
-    public synchronized ProjectProperties merge(PropertyType type) {
-        if (mProjectFolder.exists()) {
-            IAbstractFile propFile = mProjectFolder.getFile(type.mFilename);
-            if (propFile.exists()) {
-                Map<String, String> map = parsePropertyFile(propFile, null /* log */);
-                if (map != null) {
-                    for(Entry<String, String> entry : map.entrySet()) {
-                        String key = entry.getKey();
-                        String value = entry.getValue();
-                        if (!mProperties.containsKey(key) && value != null) {
-                            mProperties.put(key, value);
-                        }
-                    }
-                }
-            }
-        }
-        return this;
-    }
-
-    /**
      * Creates a new project properties object, with no properties.
-     * <p/>The file is not created until {@link #save()} is called.
+     * <p/>The file is not created until {@link ProjectPropertiesWorkingCopy#save()} is called.
      * @param projectFolderOsPath the project folder.
      * @param type the type of property file to create
      */
-    public static ProjectProperties create(String projectFolderOsPath, PropertyType type) {
+    public static ProjectPropertiesWorkingCopy create(String projectFolderOsPath,
+            PropertyType type) {
         // create and return a ProjectProperties with an empty map.
         IAbstractFolder folder = new FolderWrapper(projectFolderOsPath);
         return create(folder, type);
@@ -288,13 +244,27 @@ public final class ProjectProperties {
 
     /**
      * Creates a new project properties object, with no properties.
-     * <p/>The file is not created until {@link #save()} is called.
+     * <p/>The file is not created until {@link ProjectPropertiesWorkingCopy#save()} is called.
      * @param projectFolder the project folder.
      * @param type the type of property file to create
      */
-    public static ProjectProperties create(IAbstractFolder projectFolder, PropertyType type) {
+    public static ProjectPropertiesWorkingCopy create(IAbstractFolder projectFolder,
+            PropertyType type) {
         // create and return a ProjectProperties with an empty map.
-        return new ProjectProperties(projectFolder, new HashMap<String, String>(), type);
+        return new ProjectPropertiesWorkingCopy(projectFolder, new HashMap<String, String>(), type);
+    }
+
+    /**
+     * Creates and returns a copy of the current properties as a
+     * {@link ProjectPropertiesWorkingCopy} that can be modified and saved.
+     * @return a new instance of {@link ProjectPropertiesWorkingCopy}
+     */
+    public ProjectPropertiesWorkingCopy makeWorkingCopy() {
+        // copy the current properties in a new map
+        HashMap<String, String> propList = new HashMap<String, String>();
+        propList.putAll(mProperties);
+
+        return new ProjectPropertiesWorkingCopy(mProjectFolder, propList, mType);
     }
 
     /**
@@ -307,15 +277,6 @@ public final class ProjectProperties {
     }
 
     /**
-     * Sets a new properties. If a property with the same name already exists, it is replaced.
-     * @param name the name of the property.
-     * @param value the value of the property.
-     */
-    public synchronized void setProperty(String name, String value) {
-        mProperties.put(name, value);
-    }
-
-    /**
      * Returns the value of a property.
      * @param name the name of the property.
      * @return the property value or null if the property is not set.
@@ -325,14 +286,6 @@ public final class ProjectProperties {
     }
 
     /**
-     * Removes a property and returns its previous value (or null if the property did not exist).
-     * @param name the name of the property to remove.
-     */
-    public synchronized String removeProperty(String name) {
-        return mProperties.remove(name);
-    }
-
-    /**
      * Returns a set of the property keys. Unlike {@link Map#keySet()} this is not a view of the
      * map keys. Modifying the returned {@link Set} will not impact the underlying {@link Map}.
      */
@@ -357,112 +310,6 @@ public final class ProjectProperties {
     }
 
     /**
-     * Saves the property file, using UTF-8 encoding.
-     * @throws IOException
-     * @throws StreamException
-     */
-    public synchronized void save() throws IOException, StreamException {
-        IAbstractFile toSave = mProjectFolder.getFile(mType.mFilename);
-
-        // write the whole file in a byte array before dumping it in the file. This
-        // This is so that if the file already existing
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        OutputStreamWriter writer = new OutputStreamWriter(baos, SdkConstants.INI_CHARSET);
-
-        if (toSave.exists()) {
-            BufferedReader reader = new BufferedReader(new InputStreamReader(toSave.getContents(),
-                    SdkConstants.INI_CHARSET));
-
-            // since we're reading the existing file and replacing values with new ones, or skipping
-            // removed values, we need to record what properties have been visited, so that
-            // we can figure later what new properties need to be added at the end of the file.
-            HashSet<String> visitedProps = new HashSet<String>();
-
-            String line = null;
-            while ((line = reader.readLine()) != null) {
-                // check if this is a line containing a property.
-                if (line.length() > 0 && line.charAt(0) != '#') {
-
-                    Matcher m = PATTERN_PROP.matcher(line);
-                    if (m.matches()) {
-                        String key = m.group(1);
-                        String value = m.group(2);
-
-                        // record the prop
-                        visitedProps.add(key);
-
-                        // check if the property still exists.
-                        if (mProperties.containsKey(key)) {
-                            // put the new value.
-                            value = mProperties.get(key);
-                        } else {
-                            // property doesn't exist. Check if it's a known property.
-                            // if it's a known one, we'll remove it, otherwise, leave it untouched.
-                            if (mType.getValidProps().contains(key)) {
-                                value = null;
-                            }
-                        }
-
-                        // if the value is still valid, write it down.
-                        if (value != null) {
-                            writeValue(writer, key, value, false /*addComment*/);
-                        }
-                    } else  {
-                        // the line was wrong, let's just ignore it so that it's removed from the
-                        // file.
-                    }
-                } else {
-                    // non-property line: just write the line in the output as-is.
-                    writer.append(line).append('\n');
-                }
-            }
-
-            // now add the new properties.
-            for (Entry<String, String> entry : mProperties.entrySet()) {
-                if (visitedProps.contains(entry.getKey()) == false) {
-                    String value = entry.getValue();
-                    if (value != null) {
-                        writeValue(writer, entry.getKey(), value, true /*addComment*/);
-                    }
-                }
-            }
-
-        } else {
-            // new file, just write it all
-            // write the header
-            writer.write(mType.mHeader);
-
-            // write the properties.
-            for (Entry<String, String> entry : mProperties.entrySet()) {
-                String value = entry.getValue();
-                if (value != null) {
-                    writeValue(writer, entry.getKey(), value, true /*addComment*/);
-                }
-            }
-        }
-
-        writer.flush();
-
-        // now put the content in the file.
-        OutputStream filestream = toSave.getOutputStream();
-        filestream.write(baos.toByteArray());
-        filestream.flush();
-    }
-
-    private void writeValue(OutputStreamWriter writer, String key, String value,
-            boolean addComment) throws IOException {
-        if (addComment) {
-            String comment = COMMENT_MAP.get(key);
-            if (comment != null) {
-                writer.write(comment);
-            }
-        }
-
-        value = value.replaceAll("\\\\", "\\\\\\\\");
-        writer.write(String.format("%s=%s\n", key, value));
-    }
-
-    /**
      * Parses a property file (using UTF-8 encoding) and returns a map of the content.
      * <p/>If the file is not present, null is returned with no error messages sent to the log.
      *
@@ -540,7 +387,7 @@ public final class ProjectProperties {
      * Use {@link #load(String, PropertyType)} or {@link #create(String, PropertyType)}
      * to instantiate.
      */
-    private ProjectProperties(IAbstractFolder projectFolder, Map<String, String> map,
+    protected ProjectProperties(IAbstractFolder projectFolder, Map<String, String> map,
             PropertyType type) {
         mProjectFolder = projectFolder;
         mProperties = map;
diff --git a/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectPropertiesWorkingCopy.java b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectPropertiesWorkingCopy.java
new file mode 100644
index 0000000..e0f713c
--- /dev/null
+++ b/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/project/ProjectPropertiesWorkingCopy.java
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.sdklib.internal.project;
+
+import com.android.sdklib.SdkConstants;
+import com.android.sdklib.internal.project.ProjectProperties.PropertyType;
+import com.android.sdklib.io.IAbstractFile;
+import com.android.sdklib.io.IAbstractFolder;
+import com.android.sdklib.io.StreamException;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.regex.Matcher;
+
+/**
+ * A modifyable and saveable copy of a {@link ProjectProperties}.
+ * <p/>This copy gives access to modification method such as {@link #setProperty(String, String)}
+ * and {@link #removeProperty(String)}.
+ *
+ * To get access to an instance, use {@link ProjectProperties#makeWorkingCopy()} or
+ * {@link ProjectProperties#create(IAbstractFolder, PropertyType)}.
+ */
+@SuppressWarnings("deprecation")
+public class ProjectPropertiesWorkingCopy extends ProjectProperties {
+
+    private final static Map<String, String> COMMENT_MAP = new HashMap<String, String>();
+    static {
+//               1-------10--------20--------30--------40--------50--------60--------70--------80
+        COMMENT_MAP.put(PROPERTY_TARGET,
+                "# Project target.\n");
+        COMMENT_MAP.put(PROPERTY_SPLIT_BY_DENSITY,
+                "# Indicates whether an apk should be generated for each density.\n");
+        COMMENT_MAP.put(PROPERTY_SDK,
+                "# location of the SDK. This is only used by Ant\n" +
+                "# For customization when using a Version Control System, please read the\n" +
+                "# header note.\n");
+        COMMENT_MAP.put(PROPERTY_APP_PACKAGE,
+                "# The name of your application package as defined in the manifest.\n" +
+                "# Used by the 'uninstall' rule.\n");
+        COMMENT_MAP.put(PROPERTY_PACKAGE,
+                "# Package of the application being exported\n");
+        COMMENT_MAP.put(PROPERTY_VERSIONCODE,
+                "# Major version code\n");
+        COMMENT_MAP.put(PROPERTY_PROJECTS,
+                "# List of the Android projects being used for the export.\n" +
+                "# The list is made of paths that are relative to this project,\n" +
+                "# using forward-slash (/) as separator, and are separated by colons (:).\n");
+    }
+
+
+    /**
+     * Sets a new properties. If a property with the same name already exists, it is replaced.
+     * @param name the name of the property.
+     * @param value the value of the property.
+     */
+    public synchronized void setProperty(String name, String value) {
+        mProperties.put(name, value);
+    }
+
+    /**
+     * Removes a property and returns its previous value (or null if the property did not exist).
+     * @param name the name of the property to remove.
+     */
+    public synchronized String removeProperty(String name) {
+        return mProperties.remove(name);
+    }
+
+    /**
+     * Merges all properties from the given file into the current properties.
+     * <p/>
+     * This emulates the Ant behavior: existing properties are <em>not</em> overridden.
+     * Only new undefined properties become defined.
+     * <p/>
+     * Typical usage:
+     * <ul>
+     * <li>Create a ProjectProperties with {@link PropertyType#BUILD}
+     * <li>Merge in values using {@link PropertyType#DEFAULT}
+     * <li>The result is that this contains all the properties from default plus those
+     *     overridden by the build.properties file.
+     * </ul>
+     *
+     * @param type One the possible {@link PropertyType}s.
+     * @return this object, for chaining.
+     */
+    public synchronized ProjectPropertiesWorkingCopy merge(PropertyType type) {
+        if (mProjectFolder.exists() && mType != type) {
+            IAbstractFile propFile = mProjectFolder.getFile(type.getFilename());
+            if (propFile.exists()) {
+                Map<String, String> map = parsePropertyFile(propFile, null /* log */);
+                if (map != null) {
+                    for (Entry<String, String> entry : map.entrySet()) {
+                        String key = entry.getKey();
+                        String value = entry.getValue();
+                        if (!mProperties.containsKey(key) && value != null) {
+                            mProperties.put(key, value);
+                        }
+                    }
+                }
+            }
+        }
+        return this;
+    }
+
+
+    /**
+     * Saves the property file, using UTF-8 encoding.
+     * @throws IOException
+     * @throws StreamException
+     */
+    public synchronized void save() throws IOException, StreamException {
+        IAbstractFile toSave = mProjectFolder.getFile(mType.getFilename());
+
+        // write the whole file in a byte array before dumping it in the file. This
+        // This is so that if the file already existing
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        OutputStreamWriter writer = new OutputStreamWriter(baos, SdkConstants.INI_CHARSET);
+
+        if (toSave.exists()) {
+            BufferedReader reader = new BufferedReader(new InputStreamReader(toSave.getContents(),
+                    SdkConstants.INI_CHARSET));
+
+            // since we're reading the existing file and replacing values with new ones, or skipping
+            // removed values, we need to record what properties have been visited, so that
+            // we can figure later what new properties need to be added at the end of the file.
+            HashSet<String> visitedProps = new HashSet<String>();
+
+            String line = null;
+            while ((line = reader.readLine()) != null) {
+                // check if this is a line containing a property.
+                if (line.length() > 0 && line.charAt(0) != '#') {
+
+                    Matcher m = PATTERN_PROP.matcher(line);
+                    if (m.matches()) {
+                        String key = m.group(1);
+                        String value = m.group(2);
+
+                        // record the prop
+                        visitedProps.add(key);
+
+                        // check if the property still exists.
+                        if (mProperties.containsKey(key)) {
+                            // put the new value.
+                            value = mProperties.get(key);
+                        } else {
+                            // property doesn't exist. Check if it's a known property.
+                            // if it's a known one, we'll remove it, otherwise, leave it untouched.
+                            if (mType.isKnownProperty(key)) {
+                                value = null;
+                            }
+                        }
+
+                        // if the value is still valid, write it down.
+                        if (value != null) {
+                            writeValue(writer, key, value, false /*addComment*/);
+                        }
+                    } else  {
+                        // the line was wrong, let's just ignore it so that it's removed from the
+                        // file.
+                    }
+                } else {
+                    // non-property line: just write the line in the output as-is.
+                    writer.append(line).append('\n');
+                }
+            }
+
+            // now add the new properties.
+            for (Entry<String, String> entry : mProperties.entrySet()) {
+                if (visitedProps.contains(entry.getKey()) == false) {
+                    String value = entry.getValue();
+                    if (value != null) {
+                        writeValue(writer, entry.getKey(), value, true /*addComment*/);
+                    }
+                }
+            }
+
+        } else {
+            // new file, just write it all
+            // write the header
+            writer.write(mType.getHeader());
+
+            // write the properties.
+            for (Entry<String, String> entry : mProperties.entrySet()) {
+                String value = entry.getValue();
+                if (value != null) {
+                    writeValue(writer, entry.getKey(), value, true /*addComment*/);
+                }
+            }
+        }
+
+        writer.flush();
+
+        // now put the content in the file.
+        OutputStream filestream = toSave.getOutputStream();
+        filestream.write(baos.toByteArray());
+        filestream.flush();
+    }
+
+    private void writeValue(OutputStreamWriter writer, String key, String value,
+            boolean addComment) throws IOException {
+        if (addComment) {
+            String comment = COMMENT_MAP.get(key);
+            if (comment != null) {
+                writer.write(comment);
+            }
+        }
+
+        value = value.replaceAll("\\\\", "\\\\\\\\");
+        writer.write(String.format("%s=%s\n", key, value));
+    }
+
+    /**
+     * Private constructor.
+     * <p/>
+     * Use {@link #load(String, PropertyType)} or {@link #create(String, PropertyType)}
+     * to instantiate.
+     */
+    ProjectPropertiesWorkingCopy(IAbstractFolder projectFolder, Map<String, String> map,
+            PropertyType type) {
+        super(projectFolder, map, type);
+    }
+
+}