RecentsViewTouchHandler.java revision 931845fcb3823ce175fcfc7c6ce2d9751102c331 
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;
24import android.widget.Toast;
25
26import com.android.systemui.R;
27import com.android.systemui.recents.Recents;
28import com.android.systemui.recents.RecentsConfiguration;
29import com.android.systemui.recents.events.EventBus;
30import com.android.systemui.recents.events.ui.dragndrop.DragDropTargetChangedEvent;
31import com.android.systemui.recents.events.ui.dragndrop.DragEndEvent;
32import com.android.systemui.recents.events.ui.dragndrop.DragStartEvent;
33import com.android.systemui.recents.events.ui.dragndrop.DragStartInitializeDropTargetsEvent;
34import com.android.systemui.recents.misc.SystemServicesProxy;
35import com.android.systemui.recents.model.Task;
36import com.android.systemui.recents.model.TaskStack;
37
38import java.util.ArrayList;
39
40
41/**
42 * Represents the dock regions for each orientation.
43 */
44class DockRegion {
45    public static TaskStack.DockState[] PHONE_LANDSCAPE = {
46            // We only allow docking to the left for now on small devices
47            TaskStack.DockState.LEFT
48    };
49    public static TaskStack.DockState[] PHONE_PORTRAIT = {
50            // We only allow docking to the top for now on small devices
51            TaskStack.DockState.TOP
52    };
53    public static TaskStack.DockState[] TABLET_LANDSCAPE = {
54            TaskStack.DockState.LEFT,
55            TaskStack.DockState.RIGHT
56    };
57    public static TaskStack.DockState[] TABLET_PORTRAIT = PHONE_PORTRAIT;
58}
59
60/**
61 * Handles touch events for a RecentsView.
62 */
63public class RecentsViewTouchHandler {
64
65    private RecentsView mRv;
66
67    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task")
68    private Task mDragTask;
69    @ViewDebug.ExportedProperty(deepExport=true, prefix="drag_task_view_")
70    private TaskView mTaskView;
71
72    @ViewDebug.ExportedProperty(category="recents")
73    private Point mTaskViewOffset = new Point();
74    @ViewDebug.ExportedProperty(category="recents")
75    private Point mDownPos = new Point();
76    @ViewDebug.ExportedProperty(category="recents")
77    private boolean mDragRequested;
78    @ViewDebug.ExportedProperty(category="recents")
79    private boolean mIsDragging;
80    private float mDragSlop;
81
82    private DropTarget mLastDropTarget;
83    private ArrayList<DropTarget> mDropTargets = new ArrayList<>();
84    private ArrayList<TaskStack.DockState> mVisibleDockStates = new ArrayList<>();
85
86    public RecentsViewTouchHandler(RecentsView rv) {
87        mRv = rv;
88        mDragSlop = ViewConfiguration.get(rv.getContext()).getScaledTouchSlop();
89    }
90
91    /**
92     * Registers a new drop target for the current drag only.
93     */
94    public void registerDropTargetForCurrentDrag(DropTarget target) {
95        mDropTargets.add(target);
96    }
97
98    /**
99     * Returns the preferred dock states for the current orientation.
100     */
101    public TaskStack.DockState[] getDockStatesForCurrentOrientation() {
102        boolean isLandscape = mRv.getResources().getConfiguration().orientation ==
103                Configuration.ORIENTATION_LANDSCAPE;
104        RecentsConfiguration config = Recents.getConfiguration();
105        TaskStack.DockState[] dockStates = isLandscape ?
106                (config.isLargeScreen ? DockRegion.TABLET_LANDSCAPE : DockRegion.PHONE_LANDSCAPE) :
107                (config.isLargeScreen ? DockRegion.TABLET_PORTRAIT : DockRegion.PHONE_PORTRAIT);
108        return dockStates;
109    }
110
111    /**
112     * Returns the set of visible dock states for this current drag.
113     */
114    public ArrayList<TaskStack.DockState> getVisibleDockStates() {
115        return mVisibleDockStates;
116    }
117
118    /** Touch preprocessing for handling below */
119    public boolean onInterceptTouchEvent(MotionEvent ev) {
120        handleTouchEvent(ev);
121        return mDragRequested;
122    }
123
124    /** Handles touch events once we have intercepted them */
125    public boolean onTouchEvent(MotionEvent ev) {
126        handleTouchEvent(ev);
127        return mDragRequested;
128    }
129
130    /**** Events ****/
131
132    public final void onBusEvent(DragStartEvent event) {
133        SystemServicesProxy ssp = Recents.getSystemServices();
134        mRv.getParent().requestDisallowInterceptTouchEvent(true);
135        mDragRequested = true;
136        // We defer starting the actual drag handling until the user moves past the drag slop
137        mIsDragging = false;
138        mDragTask = event.task;
139        mTaskView = event.taskView;
140        mDropTargets.clear();
141
142        int[] recentsViewLocation = new int[2];
143        mRv.getLocationInWindow(recentsViewLocation);
144        mTaskViewOffset.set(mTaskView.getLeft() - recentsViewLocation[0] + event.tlOffset.x,
145                mTaskView.getTop() - recentsViewLocation[1] + event.tlOffset.y);
146        float x = mDownPos.x - mTaskViewOffset.x;
147        float y = mDownPos.y - mTaskViewOffset.y;
148        mTaskView.setTranslationX(x);
149        mTaskView.setTranslationY(y);
150
151        mVisibleDockStates.clear();
152        if (!ssp.hasDockedTask() && mRv.getTaskStack().getTaskCount() > 1) {
153            if (!event.task.isDockable) {
154                Toast.makeText(mRv.getContext(), R.string.recents_drag_non_dockable_task_message,
155                        Toast.LENGTH_SHORT).show();
156            } else {
157                // Add the dock state drop targets (these take priority)
158                TaskStack.DockState[] dockStates = getDockStatesForCurrentOrientation();
159                for (TaskStack.DockState dockState : dockStates) {
160                    registerDropTargetForCurrentDrag(dockState);
161                    mVisibleDockStates.add(dockState);
162                }
163            }
164        }
165
166        // Request other drop targets to register themselves
167        EventBus.getDefault().send(new DragStartInitializeDropTargetsEvent(event.task,
168                event.taskView, this));
169    }
170
171    public final void onBusEvent(DragEndEvent event) {
172        mDragRequested = false;
173        mDragTask = null;
174        mTaskView = null;
175        mLastDropTarget = null;
176    }
177
178    /**
179     * Handles dragging touch events
180     */
181    private void handleTouchEvent(MotionEvent ev) {
182        int action = ev.getAction();
183        switch (action & MotionEvent.ACTION_MASK) {
184            case MotionEvent.ACTION_DOWN:
185                mDownPos.set((int) ev.getX(), (int) ev.getY());
186                break;
187            case MotionEvent.ACTION_MOVE: {
188                float evX = ev.getX();
189                float evY = ev.getY();
190                float x = evX - mTaskViewOffset.x;
191                float y = evY - mTaskViewOffset.y;
192
193                if (mDragRequested) {
194                    if (!mIsDragging) {
195                        mIsDragging = Math.hypot(evX - mDownPos.x, evY - mDownPos.y) > mDragSlop;
196                    }
197                    if (mIsDragging) {
198                        int width = mRv.getMeasuredWidth();
199                        int height = mRv.getMeasuredHeight();
200
201                        DropTarget currentDropTarget = null;
202
203                        // Give priority to the current drop target to retain the touch handling
204                        if (mLastDropTarget != null) {
205                            if (mLastDropTarget.acceptsDrop((int) evX, (int) evY, width, height,
206                                    true /* isCurrentTarget */)) {
207                                currentDropTarget = mLastDropTarget;
208                            }
209                        }
210
211                        // Otherwise, find the next target to handle this event
212                        if (currentDropTarget == null) {
213                            for (DropTarget target : mDropTargets) {
214                                if (target.acceptsDrop((int) evX, (int) evY, width, height,
215                                        false /* isCurrentTarget */)) {
216                                    currentDropTarget = target;
217                                    break;
218                                }
219                            }
220                        }
221                        if (mLastDropTarget != currentDropTarget) {
222                            mLastDropTarget = currentDropTarget;
223                            EventBus.getDefault().send(new DragDropTargetChangedEvent(mDragTask,
224                                    currentDropTarget));
225                        }
226
227                    }
228
229                    mTaskView.setTranslationX(x);
230                    mTaskView.setTranslationY(y);
231                }
232                break;
233            }
234            case MotionEvent.ACTION_UP:
235            case MotionEvent.ACTION_CANCEL: {
236                if (mDragRequested) {
237                    EventBus.getDefault().send(new DragEndEvent(mDragTask, mTaskView,
238                            mLastDropTarget));
239                    break;
240                }
241            }
242        }
243    }
244}
245