RecentsViewTouchHandler.java revision 2068408d08ca39a5b036daac01e80de45e8c1eab 
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.app.ActivityManager;
20import android.content.res.Configuration;
21import android.graphics.Point;
22import android.view.MotionEvent;
23import android.view.ViewConfiguration;
24import android.view.ViewDebug;
25import android.widget.Toast;
26
27import com.android.systemui.R;
28import com.android.systemui.recents.Recents;
29import com.android.systemui.recents.RecentsConfiguration;
30import com.android.systemui.recents.events.EventBus;
31import com.android.systemui.recents.events.ui.dragndrop.DragDropTargetChangedEvent;
32import com.android.systemui.recents.events.ui.dragndrop.DragEndEvent;
33import com.android.systemui.recents.events.ui.dragndrop.DragStartEvent;
34import com.android.systemui.recents.events.ui.dragndrop.DragStartInitializeDropTargetsEvent;
35import com.android.systemui.recents.misc.SystemServicesProxy;
36import com.android.systemui.recents.model.Task;
37import com.android.systemui.recents.model.TaskStack;
38
39import java.util.ArrayList;
40
41
42/**
43 * Represents the dock regions for each orientation.
44 */
45class DockRegion {
46    public static TaskStack.DockState[] PHONE_LANDSCAPE = {
47            // We only allow docking to the left for now on small devices
48            TaskStack.DockState.LEFT
49    };
50    public static TaskStack.DockState[] PHONE_PORTRAIT = {
51            // We only allow docking to the top for now on small devices
52            TaskStack.DockState.TOP
53    };
54    public static TaskStack.DockState[] TABLET_LANDSCAPE = {
55            TaskStack.DockState.LEFT,
56            TaskStack.DockState.RIGHT
57    };
58    public static TaskStack.DockState[] TABLET_PORTRAIT = PHONE_PORTRAIT;
59}
60
61/**
62 * Handles touch events for a RecentsView.
63 */
64public class RecentsViewTouchHandler {
65
66    private RecentsView mRv;
67
68    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task")
69    private Task mDragTask;
70    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task_view_")
71    private TaskView mTaskView;
72
73    @ViewDebug.ExportedProperty(category="recents")
74    private Point mTaskViewOffset = new Point();
75    @ViewDebug.ExportedProperty(category="recents")
76    private Point mDownPos = new Point();
77    @ViewDebug.ExportedProperty(category="recents")
78    private boolean mDragRequested;
79    @ViewDebug.ExportedProperty(category="recents")
80    private boolean mIsDragging;
81    private float mDragSlop;
82
83    private DropTarget mLastDropTarget;
84    private ArrayList<DropTarget> mDropTargets = new ArrayList<>();
85    private ArrayList<TaskStack.DockState> mVisibleDockStates = new ArrayList<>();
86
87    public RecentsViewTouchHandler(RecentsView rv) {
88        mRv = rv;
89        mDragSlop = ViewConfiguration.get(rv.getContext()).getScaledTouchSlop();
90    }
91
92    /**
93     * Registers a new drop target for the current drag only.
94     */
95    public void registerDropTargetForCurrentDrag(DropTarget target) {
96        mDropTargets.add(target);
97    }
98
99    /**
100     * Returns the preferred dock states for the current orientation.
101     */
102    public TaskStack.DockState[] getDockStatesForCurrentOrientation() {
103        boolean isLandscape = mRv.getResources().getConfiguration().orientation ==
104                Configuration.ORIENTATION_LANDSCAPE;
105        RecentsConfiguration config = Recents.getConfiguration();
106        TaskStack.DockState[] dockStates = isLandscape ?
107                (config.isLargeScreen ? DockRegion.TABLET_LANDSCAPE : DockRegion.PHONE_LANDSCAPE) :
108                (config.isLargeScreen ? DockRegion.TABLET_PORTRAIT : DockRegion.PHONE_PORTRAIT);
109        return dockStates;
110    }
111
112    /**
113     * Returns the set of visible dock states for this current drag.
114     */
115    public ArrayList<TaskStack.DockState> getVisibleDockStates() {
116        return mVisibleDockStates;
117    }
118
119    /** Touch preprocessing for handling below */
120    public boolean onInterceptTouchEvent(MotionEvent ev) {
121        handleTouchEvent(ev);
122        return mDragRequested;
123    }
124
125    /** Handles touch events once we have intercepted them */
126    public boolean onTouchEvent(MotionEvent ev) {
127        handleTouchEvent(ev);
128        return mDragRequested;
129    }
130
131    /**** Events ****/
132
133    public final void onBusEvent(DragStartEvent event) {
134        SystemServicesProxy ssp = Recents.getSystemServices();
135        mRv.getParent().requestDisallowInterceptTouchEvent(true);
136        mDragRequested = true;
137        // We defer starting the actual drag handling until the user moves past the drag slop
138        mIsDragging = false;
139        mDragTask = event.task;
140        mTaskView = event.taskView;
141        mDropTargets.clear();
142
143        int[] recentsViewLocation = new int[2];
144        mRv.getLocationInWindow(recentsViewLocation);
145        mTaskViewOffset.set(mTaskView.getLeft() - recentsViewLocation[0] + event.tlOffset.x,
146                mTaskView.getTop() - recentsViewLocation[1] + event.tlOffset.y);
147        float x = mDownPos.x - mTaskViewOffset.x;
148        float y = mDownPos.y - mTaskViewOffset.y;
149        mTaskView.setTranslationX(x);
150        mTaskView.setTranslationY(y);
151
152        mVisibleDockStates.clear();
153        if (ActivityManager.supportsMultiWindow() && !ssp.hasDockedTask()) {
154            if (!event.task.isDockable) {
155                Toast.makeText(mRv.getContext(), R.string.recents_drag_non_dockable_task_message,
156                        Toast.LENGTH_SHORT).show();
157            } else {
158                // Add the dock state drop targets (these take priority)
159                TaskStack.DockState[] dockStates = getDockStatesForCurrentOrientation();
160                for (TaskStack.DockState dockState : dockStates) {
161                    registerDropTargetForCurrentDrag(dockState);
162                    mVisibleDockStates.add(dockState);
163                }
164            }
165        }
166
167        // Request other drop targets to register themselves
168        EventBus.getDefault().send(new DragStartInitializeDropTargetsEvent(event.task,
169                event.taskView, this));
170    }
171
172    public final void onBusEvent(DragEndEvent event) {
173        mDragRequested = false;
174        mDragTask = null;
175        mTaskView = null;
176        mLastDropTarget = null;
177    }
178
179    /**
180     * Handles dragging touch events
181     */
182    private void handleTouchEvent(MotionEvent ev) {
183        int action = ev.getAction();
184        switch (action & MotionEvent.ACTION_MASK) {
185            case MotionEvent.ACTION_DOWN:
186                mDownPos.set((int) ev.getX(), (int) ev.getY());
187                break;
188            case MotionEvent.ACTION_MOVE: {
189                float evX = ev.getX();
190                float evY = ev.getY();
191                float x = evX - mTaskViewOffset.x;
192                float y = evY - mTaskViewOffset.y;
193
194                if (mDragRequested) {
195                    if (!mIsDragging) {
196                        mIsDragging = Math.hypot(evX - mDownPos.x, evY - mDownPos.y) > mDragSlop;
197                    }
198                    if (mIsDragging) {
199                        int width = mRv.getMeasuredWidth();
200                        int height = mRv.getMeasuredHeight();
201
202                        DropTarget currentDropTarget = null;
203
204                        // Give priority to the current drop target to retain the touch handling
205                        if (mLastDropTarget != null) {
206                            if (mLastDropTarget.acceptsDrop((int) evX, (int) evY, width, height,
207                                    true /* isCurrentTarget */)) {
208                                currentDropTarget = mLastDropTarget;
209                            }
210                        }
211
212                        // Otherwise, find the next target to handle this event
213                        if (currentDropTarget == null) {
214                            for (DropTarget target : mDropTargets) {
215                                if (target.acceptsDrop((int) evX, (int) evY, width, height,
216                                        false /* isCurrentTarget */)) {
217                                    currentDropTarget = target;
218                                    break;
219                                }
220                            }
221                        }
222                        if (mLastDropTarget != currentDropTarget) {
223                            mLastDropTarget = currentDropTarget;
224                            EventBus.getDefault().send(new DragDropTargetChangedEvent(mDragTask,
225                                    currentDropTarget));
226                        }
227
228                    }
229
230                    mTaskView.setTranslationX(x);
231                    mTaskView.setTranslationY(y);
232                }
233                break;
234            }
235            case MotionEvent.ACTION_UP:
236            case MotionEvent.ACTION_CANCEL: {
237                if (mDragRequested) {
238                    EventBus.getDefault().send(new DragEndEvent(mDragTask, mTaskView,
239                            mLastDropTarget));
240                    break;
241                }
242            }
243        }
244    }
245}
246