diff options
Diffstat (limited to 'src/com/android/launcher3/DropTarget.java')
| -rw-r--r-- | src/com/android/launcher3/DropTarget.java | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/com/android/launcher3/DropTarget.java b/src/com/android/launcher3/DropTarget.java new file mode 100644 index 000000000..3ecb8ff08 --- /dev/null +++ b/src/com/android/launcher3/DropTarget.java @@ -0,0 +1,184 @@ +/* + * Copyright (C) 2008 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.launcher3; + +import android.content.Context; +import android.graphics.PointF; +import android.graphics.Rect; +import android.util.Log; + +/** + * Interface defining an object that can receive a drag. + * + */ +public interface DropTarget { + + public static final String TAG = "DropTarget"; + + class DragObject { + public int x = -1; + public int y = -1; + + /** X offset from the upper-left corner of the cell to where we touched. */ + public int xOffset = -1; + + /** Y offset from the upper-left corner of the cell to where we touched. */ + public int yOffset = -1; + + /** This indicates whether a drag is in final stages, either drop or cancel. It + * differentiates onDragExit, since this is called when the drag is ending, above + * the current drag target, or when the drag moves off the current drag object. + */ + public boolean dragComplete = false; + + /** The view that moves around while you drag. */ + public DragView dragView = null; + + /** The data associated with the object being dragged */ + public Object dragInfo = null; + + /** Where the drag originated */ + public DragSource dragSource = null; + + /** Post drag animation runnable */ + public Runnable postAnimationRunnable = null; + + /** Indicates that the drag operation was cancelled */ + public boolean cancelled = false; + + /** Defers removing the DragView from the DragLayer until after the drop animation. */ + public boolean deferDragViewCleanupPostAnimation = true; + + public DragObject() { + } + } + + public static class DragEnforcer implements DragController.DragListener { + int dragParity = 0; + + public DragEnforcer(Context context) { + Launcher launcher = (Launcher) context; + launcher.getDragController().addDragListener(this); + } + + void onDragEnter() { + dragParity++; + if (dragParity != 1) { + Log.e(TAG, "onDragEnter: Drag contract violated: " + dragParity); + } + } + + void onDragExit() { + dragParity--; + if (dragParity != 0) { + Log.e(TAG, "onDragExit: Drag contract violated: " + dragParity); + } + } + + @Override + public void onDragStart(DragSource source, Object info, int dragAction) { + if (dragParity != 0) { + Log.e(TAG, "onDragEnter: Drag contract violated: " + dragParity); + } + } + + @Override + public void onDragEnd() { + if (dragParity != 0) { + Log.e(TAG, "onDragExit: Drag contract violated: " + dragParity); + } + } + } + + /** + * Used to temporarily disable certain drop targets + * + * @return boolean specifying whether this drop target is currently enabled + */ + boolean isDropEnabled(); + + /** + * Handle an object being dropped on the DropTarget + * + * @param source DragSource where the drag started + * @param x X coordinate of the drop location + * @param y Y coordinate of the drop location + * @param xOffset Horizontal offset with the object being dragged where the original + * touch happened + * @param yOffset Vertical offset with the object being dragged where the original + * touch happened + * @param dragView The DragView that's being dragged around on screen. + * @param dragInfo Data associated with the object being dragged + * + */ + void onDrop(DragObject dragObject); + + void onDragEnter(DragObject dragObject); + + void onDragOver(DragObject dragObject); + + void onDragExit(DragObject dragObject); + + /** + * Handle an object being dropped as a result of flinging to delete and will be called in place + * of onDrop(). (This is only called on objects that are set as the DragController's + * fling-to-delete target. + */ + void onFlingToDelete(DragObject dragObject, int x, int y, PointF vec); + + /** + * Allows a DropTarget to delegate drag and drop events to another object. + * + * Most subclasses will should just return null from this method. + * + * @param source DragSource where the drag started + * @param x X coordinate of the drop location + * @param y Y coordinate of the drop location + * @param xOffset Horizontal offset with the object being dragged where the original + * touch happened + * @param yOffset Vertical offset with the object being dragged where the original + * touch happened + * @param dragView The DragView that's being dragged around on screen. + * @param dragInfo Data associated with the object being dragged + * + * @return The DropTarget to delegate to, or null to not delegate to another object. + */ + DropTarget getDropTargetDelegate(DragObject dragObject); + + /** + * Check if a drop action can occur at, or near, the requested location. + * This will be called just before onDrop. + * + * @param source DragSource where the drag started + * @param x X coordinate of the drop location + * @param y Y coordinate of the drop location + * @param xOffset Horizontal offset with the object being dragged where the + * original touch happened + * @param yOffset Vertical offset with the object being dragged where the + * original touch happened + * @param dragView The DragView that's being dragged around on screen. + * @param dragInfo Data associated with the object being dragged + * @return True if the drop will be accepted, false otherwise. + */ + boolean acceptDrop(DragObject dragObject); + + // These methods are implemented in Views + void getHitRect(Rect outRect); + void getLocationInDragLayer(int[] loc); + int getLeft(); + int getTop(); +} |