RecentsViewTouchHandler.java revision 231bc9c54a48921f9c6a1ae187969c9bfe9d121f 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.systemui.recents.views;
18
19import android.content.res.Configuration;
20import android.graphics.Point;
21import android.view.MotionEvent;
22import android.view.ViewConfiguration;
23import android.view.ViewDebug;
24
25import com.android.systemui.recents.Recents;
26import com.android.systemui.recents.RecentsConfiguration;
27import com.android.systemui.recents.events.EventBus;
28import com.android.systemui.recents.events.ui.dragndrop.DragDropTargetChangedEvent;
29import com.android.systemui.recents.events.ui.dragndrop.DragEndEvent;
30import com.android.systemui.recents.events.ui.dragndrop.DragStartEvent;
31import com.android.systemui.recents.events.ui.dragndrop.DragStartInitializeDropTargetsEvent;
32import com.android.systemui.recents.misc.SystemServicesProxy;
33import com.android.systemui.recents.model.Task;
34import com.android.systemui.recents.model.TaskStack;
35
36import java.util.ArrayList;
37
38
39/**
40 * Represents the dock regions for each orientation.
41 */
42class DockRegion {
43    public static TaskStack.DockState[] PHONE_LANDSCAPE = {
44            // We only allow docking to the left for now on small devices
45            TaskStack.DockState.LEFT
46    };
47    public static TaskStack.DockState[] PHONE_PORTRAIT = {
48            // We only allow docking to the top for now on small devices
49            TaskStack.DockState.TOP
50    };
51    public static TaskStack.DockState[] TABLET_LANDSCAPE = {
52            TaskStack.DockState.LEFT,
53            TaskStack.DockState.RIGHT
54    };
55    public static TaskStack.DockState[] TABLET_PORTRAIT = PHONE_PORTRAIT;
56}
57
58/**
59 * Handles touch events for a RecentsView.
60 */
61public class RecentsViewTouchHandler {
62
63    private RecentsView mRv;
64
65    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task")
66    private Task mDragTask;
67    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task_view_")
68    private TaskView mTaskView;
69
70    @ViewDebug.ExportedProperty(category="recents")
71    private Point mTaskViewOffset = new Point();
72    @ViewDebug.ExportedProperty(category="recents")
73    private Point mDownPos = new Point();
74    @ViewDebug.ExportedProperty(category="recents")
75    private boolean mDragRequested;
76    @ViewDebug.ExportedProperty(category="recents")
77    private boolean mIsDragging;
78    private float mDragSlop;
79
80    private DropTarget mLastDropTarget;
81    private ArrayList<DropTarget> mDropTargets = new ArrayList<>();
82    private ArrayList<TaskStack.DockState> mVisibleDockStates = new ArrayList<>();
83
84    public RecentsViewTouchHandler(RecentsView rv) {
85        mRv = rv;
86        mDragSlop = ViewConfiguration.get(rv.getContext()).getScaledTouchSlop();
87    }
88
89    /**
90     * Registers a new drop target for the current drag only.
91     */
92    public void registerDropTargetForCurrentDrag(DropTarget target) {
93        mDropTargets.add(target);
94    }
95
96    /**
97     * Returns the preferred dock states for the current orientation.
98     */
99    public TaskStack.DockState[] getDockStatesForCurrentOrientation() {
100        boolean isLandscape = mRv.getResources().getConfiguration().orientation ==
101                Configuration.ORIENTATION_LANDSCAPE;
102        RecentsConfiguration config = Recents.getConfiguration();
103        TaskStack.DockState[] dockStates = isLandscape ?
104                (config.isLargeScreen ? DockRegion.TABLET_LANDSCAPE : DockRegion.PHONE_LANDSCAPE) :
105                (config.isLargeScreen ? DockRegion.TABLET_PORTRAIT : DockRegion.PHONE_PORTRAIT);
106        return dockStates;
107    }
108
109    /**
110     * Returns the set of visible dock states for this current drag.
111     */
112    public ArrayList<TaskStack.DockState> getVisibleDockStates() {
113        return mVisibleDockStates;
114    }
115
116    /** Touch preprocessing for handling below */
117    public boolean onInterceptTouchEvent(MotionEvent ev) {
118        handleTouchEvent(ev);
119        return mDragRequested;
120    }
121
122    /** Handles touch events once we have intercepted them */
123    public boolean onTouchEvent(MotionEvent ev) {
124        handleTouchEvent(ev);
125        return mDragRequested;
126    }
127
128    /**** Events ****/
129
130    public final void onBusEvent(DragStartEvent event) {
131        SystemServicesProxy ssp = Recents.getSystemServices();
132        mRv.getParent().requestDisallowInterceptTouchEvent(true);
133        mDragRequested = true;
134        // We defer starting the actual drag handling until the user moves past the drag slop
135        mIsDragging = false;
136        mDragTask = event.task;
137        mTaskView = event.taskView;
138        mDropTargets.clear();
139
140        int[] recentsViewLocation = new int[2];
141        mRv.getLocationInWindow(recentsViewLocation);
142        mTaskViewOffset.set(mTaskView.getLeft() - recentsViewLocation[0] + event.tlOffset.x,
143                mTaskView.getTop() - recentsViewLocation[1] + event.tlOffset.y);
144        float x = mDownPos.x - mTaskViewOffset.x;
145        float y = mDownPos.y - mTaskViewOffset.y;
146        mTaskView.setTranslationX(x);
147        mTaskView.setTranslationY(y);
148
149        mVisibleDockStates.clear();
150        if (!ssp.hasDockedTask() && mRv.getTaskStack().getTaskCount() > 1) {
151            // Add the dock state drop targets (these take priority)
152            TaskStack.DockState[] dockStates = getDockStatesForCurrentOrientation();
153            for (TaskStack.DockState dockState : dockStates) {
154                registerDropTargetForCurrentDrag(dockState);
155                mVisibleDockStates.add(dockState);
156            }
157        }
158
159        // Request other drop targets to register themselves
160        EventBus.getDefault().send(new DragStartInitializeDropTargetsEvent(event.task,
161                event.taskView, this));
162    }
163
164    public final void onBusEvent(DragEndEvent event) {
165        mDragRequested = false;
166        mDragTask = null;
167        mTaskView = null;
168        mLastDropTarget = null;
169    }
170
171    /**
172     * Handles dragging touch events
173     */
174    private void handleTouchEvent(MotionEvent ev) {
175        int action = ev.getAction();
176        switch (action & MotionEvent.ACTION_MASK) {
177            case MotionEvent.ACTION_DOWN:
178                mDownPos.set((int) ev.getX(), (int) ev.getY());
179                break;
180            case MotionEvent.ACTION_MOVE: {
181                float evX = ev.getX();
182                float evY = ev.getY();
183                float x = evX - mTaskViewOffset.x;
184                float y = evY - mTaskViewOffset.y;
185
186                if (mDragRequested) {
187                    if (!mIsDragging) {
188                        mIsDragging = Math.hypot(evX - mDownPos.x, evY - mDownPos.y) > mDragSlop;
189                    }
190                    if (mIsDragging) {
191                        int width = mRv.getMeasuredWidth();
192                        int height = mRv.getMeasuredHeight();
193
194                        DropTarget currentDropTarget = null;
195
196                        // Give priority to the current drop target to retain the touch handling
197                        if (mLastDropTarget != null) {
198                            if (mLastDropTarget.acceptsDrop((int) evX, (int) evY, width, height,
199                                    true /* isCurrentTarget */)) {
200                                currentDropTarget = mLastDropTarget;
201                            }
202                        }
203
204                        // Otherwise, find the next target to handle this event
205                        if (currentDropTarget == null) {
206                            for (DropTarget target : mDropTargets) {
207                                if (target.acceptsDrop((int) evX, (int) evY, width, height,
208                                        false /* isCurrentTarget */)) {
209                                    currentDropTarget = target;
210                                    break;
211                                }
212                            }
213                        }
214                        if (mLastDropTarget != currentDropTarget) {
215                            mLastDropTarget = currentDropTarget;
216                            EventBus.getDefault().send(new DragDropTargetChangedEvent(mDragTask,
217                                    currentDropTarget));
218                        }
219
220                    }
221
222                    mTaskView.setTranslationX(x);
223                    mTaskView.setTranslationY(y);
224                }
225                break;
226            }
227            case MotionEvent.ACTION_UP:
228            case MotionEvent.ACTION_CANCEL: {
229                if (mDragRequested) {
230                    EventBus.getDefault().send(new DragEndEvent(mDragTask, mTaskView,
231                            mLastDropTarget));
232                    break;
233                }
234            }
235        }
236    }
237}
238