RecentsViewTouchHandler.java revision 131d53a7d817560ad06b5f26dc64a2969aeed53f 
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.graphics.Rect;
23import android.view.InputDevice;
24import android.view.MotionEvent;
25import android.view.PointerIcon;
26import android.view.ViewConfiguration;
27import android.view.ViewDebug;
28
29import com.android.internal.policy.DividerSnapAlgorithm;
30import com.android.systemui.recents.Recents;
31import com.android.systemui.recents.RecentsConfiguration;
32import com.android.systemui.recents.events.EventBus;
33import com.android.systemui.recents.events.activity.ConfigurationChangedEvent;
34import com.android.systemui.recents.events.ui.HideIncompatibleAppOverlayEvent;
35import com.android.systemui.recents.events.ui.ShowIncompatibleAppOverlayEvent;
36import com.android.systemui.recents.events.ui.dragndrop.DragDropTargetChangedEvent;
37import com.android.systemui.recents.events.ui.dragndrop.DragEndEvent;
38import com.android.systemui.recents.events.ui.dragndrop.DragStartEvent;
39import com.android.systemui.recents.events.ui.dragndrop.DragStartInitializeDropTargetsEvent;
40import com.android.systemui.recents.misc.SystemServicesProxy;
41import com.android.systemui.recents.model.Task;
42import com.android.systemui.recents.model.TaskStack;
43
44import java.util.ArrayList;
45
46/**
47 * Represents the dock regions for each orientation.
48 */
49class DockRegion {
50    public static TaskStack.DockState[] PHONE_LANDSCAPE = {
51            // We only allow docking to the left for now on small devices
52            TaskStack.DockState.LEFT
53    };
54    public static TaskStack.DockState[] PHONE_PORTRAIT = {
55            // We only allow docking to the top for now on small devices
56            TaskStack.DockState.TOP
57    };
58    public static TaskStack.DockState[] TABLET_LANDSCAPE = {
59            TaskStack.DockState.LEFT,
60            TaskStack.DockState.RIGHT
61    };
62    public static TaskStack.DockState[] TABLET_PORTRAIT = PHONE_PORTRAIT;
63}
64
65/**
66 * Handles touch events for a RecentsView.
67 */
68public class RecentsViewTouchHandler {
69
70    private RecentsView mRv;
71
72    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task")
73    private Task mDragTask;
74    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task_view_")
75    private TaskView mTaskView;
76
77    @ViewDebug.ExportedProperty(category="recents")
78    private Point mTaskViewOffset = new Point();
79    @ViewDebug.ExportedProperty(category="recents")
80    private Point mDownPos = new Point();
81    @ViewDebug.ExportedProperty(category="recents")
82    private boolean mDragRequested;
83    @ViewDebug.ExportedProperty(category="recents")
84    private boolean mIsDragging;
85    private float mDragSlop;
86    private int mDeviceId = -1;
87
88    private DropTarget mLastDropTarget;
89    private DividerSnapAlgorithm mDividerSnapAlgorithm;
90    private ArrayList<DropTarget> mDropTargets = new ArrayList<>();
91    private ArrayList<TaskStack.DockState> mVisibleDockStates = new ArrayList<>();
92
93    public RecentsViewTouchHandler(RecentsView rv) {
94        mRv = rv;
95        mDragSlop = ViewConfiguration.get(rv.getContext()).getScaledTouchSlop();
96        updateSnapAlgorithm();
97    }
98
99    private void updateSnapAlgorithm() {
100        Rect insets = new Rect();
101        SystemServicesProxy.getInstance(mRv.getContext()).getStableInsets(insets);
102        mDividerSnapAlgorithm = DividerSnapAlgorithm.create(mRv.getContext(), insets);
103    }
104
105    /**
106     * Registers a new drop target for the current drag only.
107     */
108    public void registerDropTargetForCurrentDrag(DropTarget target) {
109        mDropTargets.add(target);
110    }
111
112    /**
113     * Returns the preferred dock states for the current orientation.
114     */
115    public TaskStack.DockState[] getDockStatesForCurrentOrientation() {
116        boolean isLandscape = mRv.getResources().getConfiguration().orientation ==
117                Configuration.ORIENTATION_LANDSCAPE;
118        RecentsConfiguration config = Recents.getConfiguration();
119        TaskStack.DockState[] dockStates = isLandscape ?
120                (config.isLargeScreen ? DockRegion.TABLET_LANDSCAPE : DockRegion.PHONE_LANDSCAPE) :
121                (config.isLargeScreen ? DockRegion.TABLET_PORTRAIT : DockRegion.PHONE_PORTRAIT);
122        return dockStates;
123    }
124
125    /**
126     * Returns the set of visible dock states for this current drag.
127     */
128    public ArrayList<TaskStack.DockState> getVisibleDockStates() {
129        return mVisibleDockStates;
130    }
131
132    /** Touch preprocessing for handling below */
133    public boolean onInterceptTouchEvent(MotionEvent ev) {
134        handleTouchEvent(ev);
135        return mDragRequested;
136    }
137
138    /** Handles touch events once we have intercepted them */
139    public boolean onTouchEvent(MotionEvent ev) {
140        handleTouchEvent(ev);
141        return mDragRequested;
142    }
143
144    /**** Events ****/
145
146    public final void onBusEvent(DragStartEvent event) {
147        SystemServicesProxy ssp = Recents.getSystemServices();
148        mRv.getParent().requestDisallowInterceptTouchEvent(true);
149        mDragRequested = true;
150        // We defer starting the actual drag handling until the user moves past the drag slop
151        mIsDragging = false;
152        mDragTask = event.task;
153        mTaskView = event.taskView;
154        mDropTargets.clear();
155
156        int[] recentsViewLocation = new int[2];
157        mRv.getLocationInWindow(recentsViewLocation);
158        mTaskViewOffset.set(mTaskView.getLeft() - recentsViewLocation[0] + event.tlOffset.x,
159                mTaskView.getTop() - recentsViewLocation[1] + event.tlOffset.y);
160        float x = mDownPos.x - mTaskViewOffset.x;
161        float y = mDownPos.y - mTaskViewOffset.y;
162        mTaskView.setTranslationX(x);
163        mTaskView.setTranslationY(y);
164
165        mVisibleDockStates.clear();
166        if (ActivityManager.supportsMultiWindow() && !ssp.hasDockedTask()
167                && mDividerSnapAlgorithm.isSplitScreenFeasible()) {
168            Recents.logDockAttempt(mRv.getContext(), event.task.getTopComponent(),
169                    event.task.resizeMode);
170            if (!event.task.isDockable) {
171                EventBus.getDefault().send(new ShowIncompatibleAppOverlayEvent());
172            } else {
173                // Add the dock state drop targets (these take priority)
174                TaskStack.DockState[] dockStates = getDockStatesForCurrentOrientation();
175                for (TaskStack.DockState dockState : dockStates) {
176                    registerDropTargetForCurrentDrag(dockState);
177                    dockState.update(mRv.getContext());
178                    mVisibleDockStates.add(dockState);
179                }
180            }
181        }
182
183        // Request other drop targets to register themselves
184        EventBus.getDefault().send(new DragStartInitializeDropTargetsEvent(event.task,
185                event.taskView, this));
186        if (mDeviceId != -1) {
187            InputDevice.getDevice(mDeviceId).setPointerType(PointerIcon.TYPE_GRABBING);
188        }
189    }
190
191    public final void onBusEvent(DragEndEvent event) {
192        if (!mDragTask.isDockable) {
193            EventBus.getDefault().send(new HideIncompatibleAppOverlayEvent());
194        }
195        mDragRequested = false;
196        mDragTask = null;
197        mTaskView = null;
198        mLastDropTarget = null;
199    }
200
201    public final void onBusEvent(ConfigurationChangedEvent event) {
202        if (event.fromDisplayDensityChange || event.fromDeviceOrientationChange) {
203            updateSnapAlgorithm();
204        }
205    }
206
207    /**
208     * Handles dragging touch events
209     */
210    private void handleTouchEvent(MotionEvent ev) {
211        int action = ev.getActionMasked();
212        switch (action) {
213            case MotionEvent.ACTION_DOWN:
214                mDownPos.set((int) ev.getX(), (int) ev.getY());
215                mDeviceId = ev.getDeviceId();
216                break;
217            case MotionEvent.ACTION_MOVE: {
218                float evX = ev.getX();
219                float evY = ev.getY();
220                float x = evX - mTaskViewOffset.x;
221                float y = evY - mTaskViewOffset.y;
222
223                if (mDragRequested) {
224                    if (!mIsDragging) {
225                        mIsDragging = Math.hypot(evX - mDownPos.x, evY - mDownPos.y) > mDragSlop;
226                    }
227                    if (mIsDragging) {
228                        int width = mRv.getMeasuredWidth();
229                        int height = mRv.getMeasuredHeight();
230
231                        DropTarget currentDropTarget = null;
232
233                        // Give priority to the current drop target to retain the touch handling
234                        if (mLastDropTarget != null) {
235                            if (mLastDropTarget.acceptsDrop((int) evX, (int) evY, width, height,
236                                    true /* isCurrentTarget */)) {
237                                currentDropTarget = mLastDropTarget;
238                            }
239                        }
240
241                        // Otherwise, find the next target to handle this event
242                        if (currentDropTarget == null) {
243                            for (DropTarget target : mDropTargets) {
244                                if (target.acceptsDrop((int) evX, (int) evY, width, height,
245                                        false /* isCurrentTarget */)) {
246                                    currentDropTarget = target;
247                                    break;
248                                }
249                            }
250                        }
251                        if (mLastDropTarget != currentDropTarget) {
252                            mLastDropTarget = currentDropTarget;
253                            EventBus.getDefault().send(new DragDropTargetChangedEvent(mDragTask,
254                                    currentDropTarget));
255                        }
256
257                    }
258
259                    mTaskView.setTranslationX(x);
260                    mTaskView.setTranslationY(y);
261                }
262                break;
263            }
264            case MotionEvent.ACTION_UP:
265            case MotionEvent.ACTION_CANCEL: {
266                if (mDragRequested) {
267                    boolean cancelled = action == MotionEvent.ACTION_CANCEL;
268                    if (cancelled) {
269                        EventBus.getDefault().send(new DragDropTargetChangedEvent(mDragTask, null));
270                    }
271                    EventBus.getDefault().send(new DragEndEvent(mDragTask, mTaskView,
272                            !cancelled ? mLastDropTarget : null));
273                    break;
274                }
275                mDeviceId = -1;
276            }
277        }
278    }
279}
280