RecentsViewTouchHandler.java revision c54c748ede08ee79dee2397d2e0820a4067ab3aa 
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.MotionEvent;
24import android.view.ViewConfiguration;
25import android.view.ViewDebug;
26
27import com.android.internal.policy.DividerSnapAlgorithm;
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.activity.ConfigurationChangedEvent;
32import com.android.systemui.recents.events.ui.HideIncompatibleAppOverlayEvent;
33import com.android.systemui.recents.events.ui.ShowIncompatibleAppOverlayEvent;
34import com.android.systemui.recents.events.ui.dragndrop.DragDropTargetChangedEvent;
35import com.android.systemui.recents.events.ui.dragndrop.DragEndEvent;
36import com.android.systemui.recents.events.ui.dragndrop.DragStartEvent;
37import com.android.systemui.recents.events.ui.dragndrop.DragStartInitializeDropTargetsEvent;
38import com.android.systemui.recents.misc.SystemServicesProxy;
39import com.android.systemui.recents.model.Task;
40import com.android.systemui.recents.model.TaskStack;
41
42import java.util.ArrayList;
43
44/**
45 * Represents the dock regions for each orientation.
46 */
47class DockRegion {
48    // The phone landscape dock states correspond to the opposite end of the screen that the nav bar
49    // appears
50    public static TaskStack.DockState[] PHONE_LANDSCAPE_LEFT = {
51            TaskStack.DockState.LEFT
52    };
53    public static TaskStack.DockState[] PHONE_LANDSCAPE_RIGHT = {
54            TaskStack.DockState.RIGHT
55    };
56    public static TaskStack.DockState[] PHONE_PORTRAIT = {
57            // We only allow docking to the top for now on small devices
58            TaskStack.DockState.TOP
59    };
60    public static TaskStack.DockState[] TABLET_LANDSCAPE = {
61            TaskStack.DockState.LEFT,
62            TaskStack.DockState.RIGHT
63    };
64    public static TaskStack.DockState[] TABLET_PORTRAIT = PHONE_PORTRAIT;
65}
66
67/**
68 * Handles touch events for a RecentsView.
69 */
70public class RecentsViewTouchHandler {
71
72    private RecentsView mRv;
73
74    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task")
75    private Task mDragTask;
76    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task_view_")
77    private TaskView mTaskView;
78
79    @ViewDebug.ExportedProperty(category="recents")
80    private Point mTaskViewOffset = new Point();
81    @ViewDebug.ExportedProperty(category="recents")
82    private Point mDownPos = new Point();
83    @ViewDebug.ExportedProperty(category="recents")
84    private boolean mDragRequested;
85    @ViewDebug.ExportedProperty(category="recents")
86    private boolean mIsDragging;
87    private float mDragSlop;
88
89    private DropTarget mLastDropTarget;
90    private DividerSnapAlgorithm mDividerSnapAlgorithm;
91    private ArrayList<DropTarget> mDropTargets = new ArrayList<>();
92    private ArrayList<TaskStack.DockState> mVisibleDockStates = new ArrayList<>();
93
94    public RecentsViewTouchHandler(RecentsView rv) {
95        mRv = rv;
96        mDragSlop = ViewConfiguration.get(rv.getContext()).getScaledTouchSlop();
97        updateSnapAlgorithm();
98    }
99
100    private void updateSnapAlgorithm() {
101        Rect insets = new Rect();
102        SystemServicesProxy.getInstance(mRv.getContext()).getStableInsets(insets);
103        mDividerSnapAlgorithm = DividerSnapAlgorithm.create(mRv.getContext(), insets);
104    }
105
106    /**
107     * Registers a new drop target for the current drag only.
108     */
109    public void registerDropTargetForCurrentDrag(DropTarget target) {
110        mDropTargets.add(target);
111    }
112
113    /**
114     * Returns the preferred dock states for the current orientation.
115     */
116    public TaskStack.DockState[] getDockStatesForCurrentOrientation() {
117        boolean isLandscape = mRv.getResources().getConfiguration().orientation ==
118                Configuration.ORIENTATION_LANDSCAPE;
119        RecentsConfiguration config = Recents.getConfiguration();
120        if (config.isLargeScreen) {
121            return isLandscape ? DockRegion.TABLET_LANDSCAPE : DockRegion.TABLET_PORTRAIT;
122        } else {
123            if (isLandscape) {
124                return mRv.isNavBarOnRight()
125                        ? DockRegion.PHONE_LANDSCAPE_LEFT
126                        : DockRegion.PHONE_LANDSCAPE_RIGHT;
127            } else {
128                return DockRegion.PHONE_PORTRAIT;
129            }
130        }
131    }
132
133    /**
134     * Returns the set of visible dock states for this current drag.
135     */
136    public ArrayList<TaskStack.DockState> getVisibleDockStates() {
137        return mVisibleDockStates;
138    }
139
140    /** Touch preprocessing for handling below */
141    public boolean onInterceptTouchEvent(MotionEvent ev) {
142        handleTouchEvent(ev);
143        return mDragRequested;
144    }
145
146    /** Handles touch events once we have intercepted them */
147    public boolean onTouchEvent(MotionEvent ev) {
148        handleTouchEvent(ev);
149        return mDragRequested;
150    }
151
152    /**** Events ****/
153
154    public final void onBusEvent(DragStartEvent event) {
155        SystemServicesProxy ssp = Recents.getSystemServices();
156        mRv.getParent().requestDisallowInterceptTouchEvent(true);
157        mDragRequested = true;
158        // We defer starting the actual drag handling until the user moves past the drag slop
159        mIsDragging = false;
160        mDragTask = event.task;
161        mTaskView = event.taskView;
162        mDropTargets.clear();
163
164        int[] recentsViewLocation = new int[2];
165        mRv.getLocationInWindow(recentsViewLocation);
166        mTaskViewOffset.set(mTaskView.getLeft() - recentsViewLocation[0] + event.tlOffset.x,
167                mTaskView.getTop() - recentsViewLocation[1] + event.tlOffset.y);
168        float x = mDownPos.x - mTaskViewOffset.x;
169        float y = mDownPos.y - mTaskViewOffset.y;
170        mTaskView.setTranslationX(x);
171        mTaskView.setTranslationY(y);
172
173        mVisibleDockStates.clear();
174        if (ActivityManager.supportsMultiWindow() && !ssp.hasDockedTask()
175                && mDividerSnapAlgorithm.isSplitScreenFeasible()) {
176            Recents.logDockAttempt(mRv.getContext(), event.task.getTopComponent(),
177                    event.task.resizeMode);
178            if (!event.task.isDockable) {
179                EventBus.getDefault().send(new ShowIncompatibleAppOverlayEvent());
180            } else {
181                // Add the dock state drop targets (these take priority)
182                TaskStack.DockState[] dockStates = getDockStatesForCurrentOrientation();
183                for (TaskStack.DockState dockState : dockStates) {
184                    registerDropTargetForCurrentDrag(dockState);
185                    dockState.update(mRv.getContext());
186                    mVisibleDockStates.add(dockState);
187                }
188            }
189        }
190
191        // Request other drop targets to register themselves
192        EventBus.getDefault().send(new DragStartInitializeDropTargetsEvent(event.task,
193                event.taskView, this));
194    }
195
196    public final void onBusEvent(DragEndEvent event) {
197        if (!mDragTask.isDockable) {
198            EventBus.getDefault().send(new HideIncompatibleAppOverlayEvent());
199        }
200        mDragRequested = false;
201        mDragTask = null;
202        mTaskView = null;
203        mLastDropTarget = null;
204    }
205
206    public final void onBusEvent(ConfigurationChangedEvent event) {
207        if (event.fromDisplayDensityChange || event.fromDeviceOrientationChange) {
208            updateSnapAlgorithm();
209        }
210    }
211
212    /**
213     * Handles dragging touch events
214     */
215    private void handleTouchEvent(MotionEvent ev) {
216        int action = ev.getActionMasked();
217        switch (action) {
218            case MotionEvent.ACTION_DOWN:
219                mDownPos.set((int) ev.getX(), (int) ev.getY());
220                break;
221            case MotionEvent.ACTION_MOVE: {
222                float evX = ev.getX();
223                float evY = ev.getY();
224                float x = evX - mTaskViewOffset.x;
225                float y = evY - mTaskViewOffset.y;
226
227                if (mDragRequested) {
228                    if (!mIsDragging) {
229                        mIsDragging = Math.hypot(evX - mDownPos.x, evY - mDownPos.y) > mDragSlop;
230                    }
231                    if (mIsDragging) {
232                        int width = mRv.getMeasuredWidth();
233                        int height = mRv.getMeasuredHeight();
234
235                        DropTarget currentDropTarget = null;
236
237                        // Give priority to the current drop target to retain the touch handling
238                        if (mLastDropTarget != null) {
239                            if (mLastDropTarget.acceptsDrop((int) evX, (int) evY, width, height,
240                                    true /* isCurrentTarget */)) {
241                                currentDropTarget = mLastDropTarget;
242                            }
243                        }
244
245                        // Otherwise, find the next target to handle this event
246                        if (currentDropTarget == null) {
247                            for (DropTarget target : mDropTargets) {
248                                if (target.acceptsDrop((int) evX, (int) evY, width, height,
249                                        false /* isCurrentTarget */)) {
250                                    currentDropTarget = target;
251                                    break;
252                                }
253                            }
254                        }
255                        if (mLastDropTarget != currentDropTarget) {
256                            mLastDropTarget = currentDropTarget;
257                            EventBus.getDefault().send(new DragDropTargetChangedEvent(mDragTask,
258                                    currentDropTarget));
259                        }
260
261                    }
262
263                    mTaskView.setTranslationX(x);
264                    mTaskView.setTranslationY(y);
265                }
266                break;
267            }
268            case MotionEvent.ACTION_UP:
269            case MotionEvent.ACTION_CANCEL: {
270                if (mDragRequested) {
271                    boolean cancelled = action == MotionEvent.ACTION_CANCEL;
272                    if (cancelled) {
273                        EventBus.getDefault().send(new DragDropTargetChangedEvent(mDragTask, null));
274                    }
275                    EventBus.getDefault().send(new DragEndEvent(mDragTask, mTaskView,
276                            !cancelled ? mLastDropTarget : null));
277                    break;
278                }
279            }
280        }
281    }
282}
283