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Diffstat (limited to 'core/java/android/view/ViewParent.java')
-rw-r--r-- | core/java/android/view/ViewParent.java | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/core/java/android/view/ViewParent.java b/core/java/android/view/ViewParent.java new file mode 100644 index 0000000..b456c5d --- /dev/null +++ b/core/java/android/view/ViewParent.java @@ -0,0 +1,211 @@ +/* + * Copyright (C) 2006 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 android.view; + +import android.graphics.Rect; + +/** + * Defines the responsibilities for a class that will be a parent of a View. + * This is the API that a view sees when it wants to interact with its parent. + * + */ +public interface ViewParent { + /** + * Called when something has changed which has invalidated the layout of a + * child of this view parent. This will schedule a layout pass of the view + * tree. + */ + public void requestLayout(); + + /** + * Indicates whether layout was requested on this view parent. + * + * @return true if layout was requested, false otherwise + */ + public boolean isLayoutRequested(); + + /** + * Called when a child wants the view hierarchy to gather and report + * transparent regions to the window compositor. Views that "punch" holes in + * the view hierarchy, such as SurfaceView can use this API to improve + * performance of the system. When no such a view is present in the + * hierarchy, this optimization in unnecessary and might slightly reduce the + * view hierarchy performance. + * + * @param child the view requesting the transparent region computation + * + */ + public void requestTransparentRegion(View child); + + /** + * All or part of a child is dirty and needs to be redrawn. + * + * @param child The child which is dirty + * @param r The area within the child that is invalid + */ + public void invalidateChild(View child, Rect r); + + /** + * All or part of a child is dirty and needs to be redrawn. + * + * The location array is an array of two int values which respectively + * define the left and the top position of the dirty child. + * + * This method must return the parent of this ViewParent if the specified + * rectangle must be invalidated in the parent. If the specified rectangle + * does not require invalidation in the parent or if the parent does not + * exist, this method must return null. + * + * When this method returns a non-null value, the location array must + * have been updated with the left and top coordinates of this ViewParent. + * + * @param location An array of 2 ints containing the left and top + * coordinates of the child to invalidate + * @param r The area within the child that is invalid + * + * @return the parent of this ViewParent or null + */ + public ViewParent invalidateChildInParent(int[] location, Rect r); + + /** + * Returns the parent if it exists, or null. + * + * @return a ViewParent or null if this ViewParent does not have a parent + */ + public ViewParent getParent(); + + /** + * Called when a child of this parent wants focus + * + * @param child The child of this ViewParent that wants focus. This view + * will contain the focused view. It is not necessarily the view that + * actually has focus. + * @param focused The view that is a descendant of child that actually has + * focus + */ + public void requestChildFocus(View child, View focused); + + /** + * Tell view hierarchy that the global view attributes need to be + * re-evaluated. + * + * @param child View whose attributes have changed. + */ + public void recomputeViewAttributes(View child); + + /** + * Called when a child of this parent is giving up focus + * + * @param child The view that is giving up focus + */ + public void clearChildFocus(View child); + + public boolean getChildVisibleRect(View child, Rect r, android.graphics.Point offset); + + /** + * Find the nearest view in the specified direction that wants to take focus + * + * @param v The view that currently has focus + * @param direction One of FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, and FOCUS_RIGHT + */ + public View focusSearch(View v, int direction); + + /** + * Change the z order of the child so it's on top of all other children + * + * @param child + */ + public void bringChildToFront(View child); + + /** + * Tells the parent that a new focusable view has become available. This is + * to handle transitions from the case where there are no focusable views to + * the case where the first focusable view appears. + * + * @param v The view that has become newly focusable + */ + public void focusableViewAvailable(View v); + + /** + * Bring up a context menu for the specified view or its ancestors. + * <p> + * In most cases, a subclass does not need to override this. However, if + * the subclass is added directly to the window manager (for example, + * {@link ViewManager#addView(View, android.view.ViewGroup.LayoutParams)}) + * then it should override this and show the context menu. + * + * @param originalView The source view where the context menu was first invoked + * @return true if a context menu was displayed + */ + public boolean showContextMenuForChild(View originalView); + + /** + * Have the parent populate the specified context menu if it has anything to + * add (and then recurse on its parent). + * + * @param menu The menu to populate + */ + public void createContextMenu(ContextMenu menu); + + /** + * This method is called on the parent when a child's drawable state + * has changed. + * + * @param child The child whose drawable state has changed. + */ + public void childDrawableStateChanged(View child); + + /** + * Called when a child does not want this parent and its ancestors to + * intercept touch events with + * {@link ViewGroup#onInterceptTouchEvent(MotionEvent)}. + * <p> + * This parent should pass this call onto its parents. This parent must obey + * this request for the duration of the touch (that is, only clear the flag + * after this parent has received an up or a cancel. + * + * @param disallowIntercept True if the child does not want the parent to + * intercept touch events. + */ + public void requestDisallowInterceptTouchEvent(boolean disallowIntercept); + + /** + * Called when a child of this group wants a particular rectangle to be + * positioned onto the screen. {@link ViewGroup}s overriding this can trust + * that: + * <ul> + * <li>child will be a direct child of this group</li> + * <li>rectangle will be in the child's coordinates</li> + * </ul> + * + * <p>{@link ViewGroup}s overriding this should uphold the contract:</p> + * <ul> + * <li>nothing will change if the rectangle is already visible</li> + * <li>the view port will be scrolled only just enough to make the + * rectangle visible</li> + * <ul> + * + * @param child The direct child making the request. + * @param rectangle The rectangle in the child's coordinates the child + * wishes to be on the screen. + * @param immediate True to forbid animated or delayed scrolling, + * false otherwise + * @return Whether the group scrolled to handle the operation + */ + public boolean requestChildRectangleOnScreen(View child, Rect rectangle, + boolean immediate); +} |