Add support for custom tab views in TabHost and TabWidget.

This change adds the ability to specify an arbitrary view for a tab
indicator.  It also adds support for specifying a drawable to use as
the divider between tab views.

2 files changed, 128 insertions, 20 deletions

diff --git a/core/java/android/widget/TabHost.java b/core/java/android/widget/TabHost.java
index 5bf8035..103d44d 100644
--- a/core/java/android/widget/TabHost.java
+++ b/core/java/android/widget/TabHost.java
@@ -177,7 +177,7 @@ mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
             // leaving touch mode.. if nothing has focus, let's give it to
             // the indicator of the current tab
             if (!mCurrentView.hasFocus() || mCurrentView.isFocused()) {
-                mTabWidget.getChildAt(mCurrentTab).requestFocus();
+                mTabWidget.getChildTabViewAt(mCurrentTab).requestFocus();
             }
         }
     }
@@ -197,6 +197,12 @@ mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
         }
         View tabIndicator = tabSpec.mIndicatorStrategy.createIndicatorView();
         tabIndicator.setOnKeyListener(mTabKeyListener);
+
+        // If this is a custom view, then do not draw the bottom strips for
+        // the tab indicators.
+        if (tabSpec.mIndicatorStrategy instanceof ViewIndicatorStrategy) {
+            mTabWidget.setDrawBottomStrips(false);
+        }
         mTabWidget.addView(tabIndicator);
         mTabSpecs.add(tabSpec);
 
@@ -235,7 +241,7 @@ mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
 
     public View getCurrentTabView() {
         if (mCurrentTab >= 0 && mCurrentTab < mTabSpecs.size()) {
-            return mTabWidget.getChildAt(mCurrentTab);
+            return mTabWidget.getChildTabViewAt(mCurrentTab);
         }
         return null;
     }
@@ -273,7 +279,7 @@ mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
                 && (mCurrentView.isRootNamespace())
                 && (mCurrentView.hasFocus())
                 && (mCurrentView.findFocus().focusSearch(View.FOCUS_UP) == null)) {
-            mTabWidget.getChildAt(mCurrentTab).requestFocus();
+            mTabWidget.getChildTabViewAt(mCurrentTab).requestFocus();
             playSoundEffect(SoundEffectConstants.NAVIGATION_UP);
             return true;
         }
@@ -411,6 +417,14 @@ mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
         }
 
         /**
+         * Specify a view as the tab indicator.
+         */
+        public TabSpec setIndicator(View view) {
+            mIndicatorStrategy = new ViewIndicatorStrategy(view);
+            return this;
+        }
+
+        /**
          * Specify the id of the view that should be used as the content
          * of the tab.
          */
@@ -437,7 +451,7 @@ mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
         }
 
 
-        String getTag() {
+        public String getTag() {
             return mTag;
         }
     }
@@ -526,6 +540,22 @@ mTabHost.addTab(TAB_TAG_1, "Hello, world!", "Tab 1");
     }
 
     /**
+     * How to create a tab indicator by specifying a view.
+     */
+    private class ViewIndicatorStrategy implements IndicatorStrategy {
+
+        private final View mView;
+
+        private ViewIndicatorStrategy(View view) {
+            mView = view;
+        }
+
+        public View createIndicatorView() {
+            return mView;
+        }
+    }
+
+    /**
      * How to create the tab content via a view id.
      */
     private class ViewIdContentStrategy implements ContentStrategy {
diff --git a/core/java/android/widget/TabWidget.java b/core/java/android/widget/TabWidget.java
index 20cddcb..a26bfa2 100644
--- a/core/java/android/widget/TabWidget.java
+++ b/core/java/android/widget/TabWidget.java
@@ -49,6 +49,8 @@ public class TabWidget extends LinearLayout implements OnFocusChangeListener {
     private Drawable mBottomLeftStrip;
     private Drawable mBottomRightStrip;
     private boolean mStripMoved;
+    private Drawable mDividerDrawable;
+    private boolean mDrawBottomStrips = true;
 
     public TabWidget(Context context) {
         this(context, null);
@@ -87,9 +89,68 @@ public class TabWidget extends LinearLayout implements OnFocusChangeListener {
         setOnFocusChangeListener(this);
     }
 
+    /**
+     * Returns the tab indicator view at the given index.
+     *
+     * @param index the zero-based index of the tab indicator view to return
+     * @return the tab indicator view at the given index
+     */
+    public View getChildTabViewAt(int index) {
+        // If we are using dividers, then instead of tab views at 0, 1, 2, ...
+        // we have tab views at 0, 2, 4, ...
+        if (mDividerDrawable != null) {
+            index *= 2;
+        }
+        return getChildAt(index);
+    }
+
+    /**
+     * Returns the number of tab indicator views.
+     * @return the number of tab indicator views.
+     */
+    public int getTabCount() {
+        int children = getChildCount();
+
+        // If we have dividers, then we will always have an odd number of
+        // children: 1, 3, 5, ... and we want to convert that sequence to
+        // this: 1, 2, 3, ...
+        if (mDividerDrawable != null) {
+            children = (children + 1) / 2;
+        }
+        return children;
+    }
+
+    /**
+     * Sets the drawable to use as a divider between the tab indicators.
+     * @param drawable the divider drawable
+     */
+    public void setDividerDrawable(Drawable drawable) {
+        mDividerDrawable = drawable;
+    }
+
+    /**
+     * Sets the drawable to use as a divider between the tab indicators.
+     * @param resId the resource identifier of the drawable to use as a
+     * divider.
+     */
+    public void setDividerDrawable(int resId) {
+        mDividerDrawable = mContext.getResources().getDrawable(resId);
+    }
+
+    /**
+     * Controls whether the bottom strips on the tab indicators are drawn or
+     * not.  The default is to draw them.  If the user specifies a custom
+     * view for the tab indicators, then the TabHost class calls this method
+     * to disable drawing of the bottom strips.
+     * @param drawBottomStrips true if the bottom strips should be drawn.
+     */
+    void setDrawBottomStrips(boolean drawBottomStrips) {
+        mDrawBottomStrips = drawBottomStrips;
+    }
+
     @Override
     public void childDrawableStateChanged(View child) {
-        if (child == getChildAt(mSelectedTab)) {
+        if (child == getChildTabViewAt(mSelectedTab)) {
             // To make sure that the bottom strip is redrawn
             invalidate();
         }
@@ -100,7 +161,14 @@ public class TabWidget extends LinearLayout implements OnFocusChangeListener {
     public void dispatchDraw(Canvas canvas) {
         super.dispatchDraw(canvas);
 
-        View selectedChild = getChildAt(mSelectedTab);
+        // If the user specified a custom view for the tab indicators, then
+        // do not draw the bottom strips.
+        if (!mDrawBottomStrips) {
+            // Skip drawing the bottom strips.
+            return;
+        }
+
+        View selectedChild = getChildTabViewAt(mSelectedTab);
         
         mBottomLeftStrip.setState(selectedChild.getDrawableState());
         mBottomRightStrip.setState(selectedChild.getDrawableState());
@@ -157,13 +225,13 @@ public class TabWidget extends LinearLayout implements OnFocusChangeListener {
      *  @see #focusCurrentTab
      */
     public void setCurrentTab(int index) {
-        if (index < 0 || index >= getChildCount()) {
+        if (index < 0 || index >= getTabCount()) {
             return;
         }
 
-        getChildAt(mSelectedTab).setSelected(false);
+        getChildTabViewAt(mSelectedTab).setSelected(false);
         mSelectedTab = index;
-        getChildAt(mSelectedTab).setSelected(true);
+        getChildTabViewAt(mSelectedTab).setSelected(true);
         mStripMoved = true;
     }
     
@@ -189,17 +257,17 @@ public class TabWidget extends LinearLayout implements OnFocusChangeListener {
         
         // change the focus if applicable.
         if (oldTab != index) {
-            getChildAt(index).requestFocus();
+            getChildTabViewAt(index).requestFocus();
         }
     }
     
     @Override
     public void setEnabled(boolean enabled) {
         super.setEnabled(enabled);
-        int count = getChildCount();
+        int count = getTabCount();
         
-        for (int i=0; i<count; i++) {
-            View child = getChildAt(i);
+        for (int i = 0; i < count; i++) {
+            View child = getChildTabViewAt(i);
             child.setEnabled(enabled);
         }
     }
@@ -218,17 +286,26 @@ public class TabWidget extends LinearLayout implements OnFocusChangeListener {
         child.setFocusable(true);
         child.setClickable(true);
 
+        // If we have dividers between the tabs and we already have at least one
+        // tab, then add a divider before adding the next tab.
+        if (mDividerDrawable != null && getTabCount() > 0) {
+            View divider = new View(mContext);
+            final LinearLayout.LayoutParams lp = new LayoutParams(
+                    mDividerDrawable.getIntrinsicWidth(),
+                    mDividerDrawable.getIntrinsicHeight());
+            lp.setMargins(0, 0, 0, 0);
+            divider.setLayoutParams(lp);
+            divider.setBackgroundDrawable(mDividerDrawable);
+            super.addView(divider);
+        }
         super.addView(child);
 
         // TODO: detect this via geometry with a tabwidget listener rather
         // than potentially interfere with the view's listener
-        child.setOnClickListener(new TabClickListener(getChildCount() - 1));
+        child.setOnClickListener(new TabClickListener(getTabCount() - 1));
         child.setOnFocusChangeListener(this);
     }
 
-
-
-
     /**
      * Provides a way for {@link TabHost} to be notified that the user clicked on a tab indicator.
      */
@@ -238,14 +315,15 @@ public class TabWidget extends LinearLayout implements OnFocusChangeListener {
 
     public void onFocusChange(View v, boolean hasFocus) {
         if (v == this && hasFocus) {
-            getChildAt(mSelectedTab).requestFocus();
+            getChildTabViewAt(mSelectedTab).requestFocus();
             return;
         }
         
         if (hasFocus) {
             int i = 0;
-            while (i < getChildCount()) {
-                if (getChildAt(i) == v) {
+            int numTabs = getTabCount();
+            while (i < numTabs) {
+                if (getChildTabViewAt(i) == v) {
                     setCurrentTab(i);
                     mSelectionChangedListener.onTabSelectionChanged(i, false);
                     break;