/*
|
* 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.graphics.Rect;
|
|
import com.android.launcher3.accessibility.DragViewStateAnnouncer;
|
import com.android.launcher3.dragndrop.DragOptions;
|
import com.android.launcher3.dragndrop.DragView;
|
|
/**
|
* Interface defining an object that can receive a drag.
|
*
|
*/
|
public interface 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, after item is dropped. */
|
public ItemInfo dragInfo = null;
|
|
/** The data associated with the object being dragged */
|
public ItemInfo originalDragInfo = null;
|
|
/** Where the drag originated */
|
public DragSource dragSource = null;
|
|
/** The object is part of an accessible drag operation */
|
public boolean accessibleDrag;
|
|
/** 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 DragViewStateAnnouncer stateAnnouncer;
|
|
public DragObject() {
|
}
|
|
/**
|
* This is used to compute the visual center of the dragView. This point is then
|
* used to visualize drop locations and determine where to drop an item. The idea is that
|
* the visual center represents the user's interpretation of where the item is, and hence
|
* is the appropriate point to use when determining drop location.
|
*/
|
public final float[] getVisualCenter(float[] recycle) {
|
final float res[] = (recycle == null) ? new float[2] : recycle;
|
Rect dragRegion = dragView.getDragRegion();
|
|
// These represent the visual top and left of drag view if a dragRect was provided.
|
// If a dragRect was not provided, then they correspond to the actual view left and
|
// top, as the dragRect is in that case taken to be the entire dragView.
|
int left = x - xOffset - dragRegion.left;
|
int top = y - yOffset - dragRegion.top;
|
|
// In order to find the visual center, we shift by half the dragRect
|
res[0] = left + dragRegion.width() / 2;
|
res[1] = top + dragRegion.height() / 2;
|
|
return res;
|
}
|
}
|
|
/**
|
* 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.
|
*
|
* This will be called only if this target previously returned true for {@link #acceptDrop}. It
|
* is the responsibility of this target to exit out of the spring loaded mode (either
|
* immediately or after any pending animations).
|
*
|
* If the drop was cancelled for some reason, onDrop will never get called, the UI will
|
* automatically exit out of this mode.
|
*/
|
void onDrop(DragObject dragObject, DragOptions options);
|
|
void onDragEnter(DragObject dragObject);
|
|
void onDragOver(DragObject dragObject);
|
|
void onDragExit(DragObject dragObject);
|
|
/**
|
* Check if a drop action can occur at, or near, the requested location.
|
* This will be called just before onDrop.
|
* @return True if the drop will be accepted, false otherwise.
|
*/
|
boolean acceptDrop(DragObject dragObject);
|
|
void prepareAccessibilityDrop();
|
|
// These methods are implemented in Views
|
void getHitRectRelativeToDragLayer(Rect outRect);
|
}
|
