| 1 | // Copyright 2013 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | package org.chromium.chromoting; |
| 6 | |
| 7 | import android.app.ActionBar; |
| 8 | import android.app.Activity; |
| 9 | import android.graphics.Bitmap; |
| 10 | import android.graphics.Canvas; |
| 11 | import android.graphics.Color; |
| 12 | import android.graphics.Matrix; |
| 13 | import android.graphics.Paint; |
| 14 | import android.os.Bundle; |
| 15 | import android.os.Looper; |
| 16 | import android.text.InputType; |
| 17 | import android.util.Log; |
| 18 | import android.view.GestureDetector; |
| 19 | import android.view.MotionEvent; |
| 20 | import android.view.ScaleGestureDetector; |
| 21 | import android.view.SurfaceHolder; |
| 22 | import android.view.SurfaceView; |
| 23 | import android.view.inputmethod.EditorInfo; |
| 24 | import android.view.inputmethod.InputConnection; |
| 25 | |
| 26 | import org.chromium.chromoting.jni.JniInterface; |
| 27 | |
| 28 | /** |
| 29 | * The user interface for viewing and interacting with a specific remote host. |
| 30 | * It provides a canvas onto which the video feed is rendered, handles |
| 31 | * multitouch pan and zoom gestures, and collects and forwards input events. |
| 32 | */ |
| 33 | /** GUI element that holds the drawing canvas. */ |
| 34 | public class DesktopView extends SurfaceView implements Runnable, SurfaceHolder.Callback { |
| 35 | /** |
| 36 | * *Square* of the minimum displacement (in pixels) to be recognized as a scroll gesture. |
| 37 | * Setting this to a lower value forces more frequent canvas redraws during scrolling. |
| 38 | */ |
| 39 | private static final int MIN_SCROLL_DISTANCE = 8 * 8; |
| 40 | |
| 41 | /** |
| 42 | * Minimum change to the scaling factor to be recognized as a zoom gesture. Setting lower |
| 43 | * values here will result in more frequent canvas redraws during zooming. |
| 44 | */ |
| 45 | private static final double MIN_ZOOM_FACTOR = 0.05; |
| 46 | |
| 47 | /* |
| 48 | * These constants must match those in the generated struct protoc::MouseEvent_MouseButton. |
| 49 | */ |
| 50 | private static final int BUTTON_UNDEFINED = 0; |
| 51 | private static final int BUTTON_LEFT = 1; |
| 52 | private static final int BUTTON_RIGHT = 3; |
| 53 | |
| 54 | /** Specifies one dimension of an image. */ |
| 55 | private static enum Constraint { |
| 56 | UNDEFINED, WIDTH, HEIGHT |
| 57 | } |
| 58 | |
| 59 | private ActionBar mActionBar; |
| 60 | |
| 61 | private GestureDetector mScroller; |
| 62 | private ScaleGestureDetector mZoomer; |
| 63 | |
| 64 | /** Stores pan and zoom configuration and converts image coordinates to screen coordinates. */ |
| 65 | private Matrix mTransform; |
| 66 | |
| 67 | private int mScreenWidth; |
| 68 | private int mScreenHeight; |
| 69 | |
| 70 | /** Specifies the dimension by which the zoom level is being lower-bounded. */ |
| 71 | private Constraint mConstraint; |
| 72 | |
| 73 | /** Whether the dimension of constraint should be reckecked on the next aspect ratio change. */ |
| 74 | private boolean mRecheckConstraint; |
| 75 | |
| 76 | /** Whether the right edge of the image was visible on-screen during the last render. */ |
| 77 | private boolean mRightUsedToBeOut; |
| 78 | |
| 79 | /** Whether the bottom edge of the image was visible on-screen during the last render. */ |
| 80 | private boolean mBottomUsedToBeOut; |
| 81 | |
| 82 | private int mMouseButton; |
| 83 | private boolean mMousePressed; |
| 84 | |
| 85 | public DesktopView(Activity context) { |
| 86 | super(context); |
| 87 | |
| 88 | // Give this view keyboard focus, allowing us to customize the soft keyboard's settings. |
| 89 | setFocusableInTouchMode(true); |
| 90 | |
| 91 | mActionBar = context.getActionBar(); |
| 92 | |
| 93 | getHolder().addCallback(this); |
| 94 | DesktopListener listener = new DesktopListener(); |
| 95 | mScroller = new GestureDetector(context, listener, null, false); |
| 96 | mZoomer = new ScaleGestureDetector(context, listener); |
| 97 | |
| 98 | mTransform = new Matrix(); |
| 99 | mScreenWidth = 0; |
| 100 | mScreenHeight = 0; |
| 101 | |
| 102 | mConstraint = Constraint.UNDEFINED; |
| 103 | mRecheckConstraint = false; |
| 104 | |
| 105 | mRightUsedToBeOut = false; |
| 106 | mBottomUsedToBeOut = false; |
| 107 | |
| 108 | mMouseButton = BUTTON_UNDEFINED; |
| 109 | mMousePressed = false; |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * Redraws the canvas. This should be done on a non-UI thread or it could |
| 114 | * cause the UI to lag. Specifically, it is currently invoked on the native |
| 115 | * graphics thread using a JNI. |
| 116 | */ |
| 117 | @Override |
| 118 | public void run() { |
| 119 | if (Looper.myLooper() == Looper.getMainLooper()) { |
| 120 | Log.w("deskview", "Canvas being redrawn on UI thread"); |
| 121 | } |
| 122 | |
| 123 | Bitmap image = JniInterface.retrieveVideoFrame(); |
| 124 | Canvas canvas = getHolder().lockCanvas(); |
| 125 | synchronized (mTransform) { |
| 126 | canvas.setMatrix(mTransform); |
| 127 | |
| 128 | // Internal parameters of the transformation matrix. |
| 129 | float[] values = new float[9]; |
| 130 | mTransform.getValues(values); |
| 131 | |
| 132 | // Screen coordinates of two defining points of the image. |
| 133 | float[] topleft = {0, 0}; |
| 134 | mTransform.mapPoints(topleft); |
| 135 | float[] bottomright = {image.getWidth(), image.getHeight()}; |
| 136 | mTransform.mapPoints(bottomright); |
| 137 | |
| 138 | // Whether to rescale and recenter the view. |
| 139 | boolean recenter = false; |
| 140 | |
| 141 | if (mConstraint == Constraint.UNDEFINED) { |
| 142 | mConstraint = (double)image.getWidth()/image.getHeight() > |
| 143 | (double)mScreenWidth/mScreenHeight ? Constraint.WIDTH : Constraint.HEIGHT; |
| 144 | recenter = true; // We always rescale and recenter after a rotation. |
| 145 | } |
| 146 | |
| 147 | if (mConstraint == Constraint.WIDTH && |
| 148 | ((int)(bottomright[0] - topleft[0] + 0.5) < mScreenWidth || recenter)) { |
| 149 | // The vertical edges of the image are flush against the device's screen edges |
| 150 | // when the entire host screen is visible, and the user has zoomed out too far. |
| 151 | float imageMiddle = (float)image.getHeight() / 2; |
| 152 | float screenMiddle = (float)mScreenHeight / 2; |
| 153 | mTransform.setPolyToPoly( |
| 154 | new float[] {0, imageMiddle, image.getWidth(), imageMiddle}, 0, |
| 155 | new float[] {0, screenMiddle, mScreenWidth, screenMiddle}, 0, 2); |
| 156 | } else if (mConstraint == Constraint.HEIGHT && |
| 157 | ((int)(bottomright[1] - topleft[1] + 0.5) < mScreenHeight || recenter)) { |
| 158 | // The horizontal image edges are flush against the device's screen edges when |
| 159 | // the entire host screen is visible, and the user has zoomed out too far. |
| 160 | float imageCenter = (float)image.getWidth() / 2; |
| 161 | float screenCenter = (float)mScreenWidth / 2; |
| 162 | mTransform.setPolyToPoly( |
| 163 | new float[] {imageCenter, 0, imageCenter, image.getHeight()}, 0, |
| 164 | new float[] {screenCenter, 0, screenCenter, mScreenHeight}, 0, 2); |
| 165 | } else { |
| 166 | // It's fine for both members of a pair of image edges to be within the screen |
| 167 | // edges (or "out of bounds"); that simply means that the image is zoomed out as |
| 168 | // far as permissible. And both members of a pair can obviously be outside the |
| 169 | // screen's edges, which indicates that the image is zoomed in to far to see the |
| 170 | // whole host screen. However, if only one of a pair of edges has entered the |
| 171 | // screen, the user is attempting to scroll into a blank area of the canvas. |
| 172 | |
| 173 | // A value of true means the corresponding edge has entered the screen's borders. |
| 174 | boolean leftEdgeOutOfBounds = values[Matrix.MTRANS_X] > 0; |
| 175 | boolean topEdgeOutOfBounds = values[Matrix.MTRANS_Y] > 0; |
| 176 | boolean rightEdgeOutOfBounds = bottomright[0] < mScreenWidth; |
| 177 | boolean bottomEdgeOutOfBounds = bottomright[1] < mScreenHeight; |
| 178 | |
| 179 | // Prevent the user from scrolling past the left or right edge of the image. |
| 180 | if (leftEdgeOutOfBounds != rightEdgeOutOfBounds) { |
| 181 | if (leftEdgeOutOfBounds != mRightUsedToBeOut) { |
| 182 | // Make the left edge of the image flush with the left screen edge. |
| 183 | values[Matrix.MTRANS_X] = 0; |
| 184 | } |
| 185 | else { |
| 186 | // Make the right edge of the image flush with the right screen edge. |
| 187 | values[Matrix.MTRANS_X] += mScreenWidth - bottomright[0]; |
| 188 | } |
| 189 | } else { |
| 190 | // The else prevents this from being updated during the repositioning process, |
| 191 | // in which case the view would begin to oscillate. |
| 192 | mRightUsedToBeOut = rightEdgeOutOfBounds; |
| 193 | } |
| 194 | |
| 195 | // Prevent the user from scrolling past the top or bottom edge of the image. |
| 196 | if (topEdgeOutOfBounds != bottomEdgeOutOfBounds) { |
| 197 | if (topEdgeOutOfBounds != mBottomUsedToBeOut) { |
| 198 | // Make the top edge of the image flush with the top screen edge. |
| 199 | values[Matrix.MTRANS_Y] = 0; |
| 200 | } else { |
| 201 | // Make the bottom edge of the image flush with the bottom screen edge. |
| 202 | values[Matrix.MTRANS_Y] += mScreenHeight - bottomright[1]; |
| 203 | } |
| 204 | } |
| 205 | else { |
| 206 | // The else prevents this from being updated during the repositioning process, |
| 207 | // in which case the view would begin to oscillate. |
| 208 | mBottomUsedToBeOut = bottomEdgeOutOfBounds; |
| 209 | } |
| 210 | |
| 211 | mTransform.setValues(values); |
| 212 | } |
| 213 | |
| 214 | canvas.setMatrix(mTransform); |
| 215 | } |
| 216 | |
| 217 | canvas.drawColor(Color.BLACK); |
| 218 | canvas.drawBitmap(image, 0, 0, new Paint()); |
| 219 | getHolder().unlockCanvasAndPost(canvas); |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * Causes the next canvas redraw to perform a check for which screen dimension more tightly |
| 224 | * constrains the view of the image. This should be called between the time that a screen size |
| 225 | * change is requested and the time it actually occurs. If it is not called in such a case, the |
| 226 | * screen will not be rearranged as aggressively (which is desirable when the software keyboard |
| 227 | * appears in order to allow it to cover the image without forcing a resize). |
| 228 | */ |
| 229 | public void requestRecheckConstrainingDimension() { |
| 230 | mRecheckConstraint = true; |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * Called after the canvas is initially created, then after every |
| 235 | * subsequent resize, as when the display is rotated. |
| 236 | */ |
| 237 | @Override |
| 238 | public void surfaceChanged( |
| 239 | SurfaceHolder holder, int format, int width, int height) { |
| 240 | mActionBar.hide(); |
| 241 | |
| 242 | synchronized (mTransform) { |
| 243 | mScreenWidth = width; |
| 244 | mScreenHeight = height; |
| 245 | |
| 246 | if (mRecheckConstraint) { |
| 247 | mConstraint = Constraint.UNDEFINED; |
| 248 | mRecheckConstraint = false; |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | if (!JniInterface.redrawGraphics()) { |
| 253 | JniInterface.provideRedrawCallback(this); |
| 254 | } |
| 255 | } |
| 256 | |
| 257 | /** Called when the canvas is first created. */ |
| 258 | @Override |
| 259 | public void surfaceCreated(SurfaceHolder holder) { |
| 260 | Log.i("deskview", "DesktopView.surfaceCreated(...)"); |
| 261 | } |
| 262 | |
| 263 | /** |
| 264 | * Called when the canvas is finally destroyed. Marks the canvas as needing a redraw so that it |
| 265 | * will not be blank if the user later switches back to our window. |
| 266 | */ |
| 267 | @Override |
| 268 | public void surfaceDestroyed(SurfaceHolder holder) { |
| 269 | Log.i("deskview", "DesktopView.surfaceDestroyed(...)"); |
| 270 | |
| 271 | // Stop this canvas from being redrawn. |
| 272 | JniInterface.provideRedrawCallback(null); |
| 273 | } |
| 274 | |
| 275 | /** Called when a software keyboard is requested, and specifies its options. */ |
| 276 | @Override |
| 277 | public InputConnection onCreateInputConnection(EditorInfo outAttrs) { |
| 278 | // Disables rich input support and instead requests simple key events. |
| 279 | outAttrs.inputType = InputType.TYPE_NULL; |
| 280 | |
| 281 | // Prevents most third-party IMEs from ignoring our Activity's adjustResize preference. |
| 282 | outAttrs.imeOptions |= EditorInfo.IME_FLAG_NO_FULLSCREEN; |
| 283 | |
| 284 | // Ensures that keyboards will not decide to hide the remote desktop on small displays. |
| 285 | outAttrs.imeOptions |= EditorInfo.IME_FLAG_NO_EXTRACT_UI; |
| 286 | |
| 287 | // Stops software keyboards from closing as soon as the enter key is pressed. |
| 288 | outAttrs.imeOptions |= EditorInfo.IME_MASK_ACTION | EditorInfo.IME_FLAG_NO_ENTER_ACTION; |
| 289 | |
| 290 | return null; |
| 291 | } |
| 292 | |
| 293 | /** Called when a mouse action is made. */ |
| 294 | private void handleMouseMovement(float x, float y, int button, boolean pressed) { |
| 295 | float[] coordinates = {x, y}; |
| 296 | |
| 297 | // Coordinates are relative to the canvas, but we need image coordinates. |
| 298 | Matrix canvasToImage = new Matrix(); |
| 299 | mTransform.invert(canvasToImage); |
| 300 | canvasToImage.mapPoints(coordinates); |
| 301 | |
| 302 | // Coordinates are now relative to the image, so transmit them to the host. |
| 303 | JniInterface.mouseAction((int)coordinates[0], (int)coordinates[1], button, pressed); |
| 304 | } |
| 305 | |
| 306 | /** |
| 307 | * Called whenever the user attempts to touch the canvas. Forwards such |
| 308 | * events to the appropriate gesture detector until one accepts them. |
| 309 | */ |
| 310 | @Override |
| 311 | public boolean onTouchEvent(MotionEvent event) { |
| 312 | if (event.getPointerCount() == 3) { |
| 313 | mActionBar.show(); |
| 314 | } |
| 315 | |
| 316 | boolean handled = mScroller.onTouchEvent(event) || mZoomer.onTouchEvent(event); |
| 317 | |
| 318 | if (event.getPointerCount() == 1) { |
| 319 | float x = event.getRawX(); |
| 320 | float y = event.getY(); |
| 321 | |
| 322 | switch (event.getActionMasked()) { |
| 323 | case MotionEvent.ACTION_DOWN: |
| 324 | Log.i("mouse", "Found a finger"); |
| 325 | mMouseButton = BUTTON_UNDEFINED; |
| 326 | mMousePressed = false; |
| 327 | break; |
| 328 | |
| 329 | case MotionEvent.ACTION_MOVE: |
| 330 | Log.i("mouse", "Finger is dragging"); |
| 331 | if (mMouseButton == BUTTON_UNDEFINED) { |
| 332 | Log.i("mouse", "\tStarting left click"); |
| 333 | mMouseButton = BUTTON_LEFT; |
| 334 | mMousePressed = true; |
| 335 | } |
| 336 | break; |
| 337 | |
| 338 | case MotionEvent.ACTION_UP: |
| 339 | Log.i("mouse", "Lost the finger"); |
| 340 | if (mMouseButton == BUTTON_UNDEFINED) { |
| 341 | // The user pressed and released without moving: do left click and release. |
| 342 | Log.i("mouse", "\tStarting and finishing left click"); |
| 343 | handleMouseMovement(x, y, BUTTON_LEFT, true); |
| 344 | mMouseButton = BUTTON_LEFT; |
| 345 | mMousePressed = false; |
| 346 | } |
| 347 | else if (mMousePressed) { |
| 348 | Log.i("mouse", "\tReleasing the currently-pressed button"); |
| 349 | mMousePressed = false; |
| 350 | } |
| 351 | else { |
| 352 | Log.w("mouse", "Button already in released state before gesture ended"); |
| 353 | } |
| 354 | break; |
| 355 | |
| 356 | default: |
| 357 | return handled; |
| 358 | } |
| 359 | handleMouseMovement(x, y, mMouseButton, mMousePressed); |
| 360 | |
| 361 | return true; |
| 362 | } |
| 363 | |
| 364 | return handled; |
| 365 | } |
| 366 | |
| 367 | /** Responds to touch events filtered by the gesture detectors. */ |
| 368 | private class DesktopListener extends GestureDetector.SimpleOnGestureListener |
| 369 | implements ScaleGestureDetector.OnScaleGestureListener { |
| 370 | /** |
| 371 | * Called when the user is scrolling. We refuse to accept or process the event unless it |
| 372 | * is being performed with 2 or more touch points, in order to reserve single-point touch |
| 373 | * events for emulating mouse input. |
| 374 | */ |
| 375 | @Override |
| 376 | public boolean onScroll( |
| 377 | MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { |
| 378 | if (e2.getPointerCount() < 2 || |
| 379 | Math.pow(distanceX, 2) + Math.pow(distanceY, 2) < MIN_SCROLL_DISTANCE) { |
| 380 | return false; |
| 381 | } |
| 382 | |
| 383 | synchronized (mTransform) { |
| 384 | mTransform.postTranslate(-distanceX, -distanceY); |
| 385 | } |
| 386 | JniInterface.redrawGraphics(); |
| 387 | return true; |
| 388 | } |
| 389 | |
| 390 | /** Called when the user is in the process of pinch-zooming. */ |
| 391 | @Override |
| 392 | public boolean onScale(ScaleGestureDetector detector) { |
| 393 | if (Math.abs(detector.getScaleFactor() - 1) < MIN_ZOOM_FACTOR) { |
| 394 | return false; |
| 395 | } |
| 396 | |
| 397 | synchronized (mTransform) { |
| 398 | float scaleFactor = detector.getScaleFactor(); |
| 399 | mTransform.postScale( |
| 400 | scaleFactor, scaleFactor, detector.getFocusX(), detector.getFocusY()); |
| 401 | } |
| 402 | JniInterface.redrawGraphics(); |
| 403 | return true; |
| 404 | } |
| 405 | |
| 406 | /** Called whenever a gesture starts. Always accepts the gesture so it isn't ignored. */ |
| 407 | @Override |
| 408 | public boolean onDown(MotionEvent e) { |
| 409 | return true; |
| 410 | } |
| 411 | |
| 412 | /** |
| 413 | * Called when the user starts to zoom. Always accepts the zoom so that |
| 414 | * onScale() can decide whether to respond to it. |
| 415 | */ |
| 416 | @Override |
| 417 | public boolean onScaleBegin(ScaleGestureDetector detector) { |
| 418 | return true; |
| 419 | } |
| 420 | |
| 421 | /** Called when the user is done zooming. Defers to onScale()'s judgement. */ |
| 422 | @Override |
| 423 | public void onScaleEnd(ScaleGestureDetector detector) { |
| 424 | onScale(detector); |
| 425 | } |
| 426 | |
| 427 | /** Called when the user holds down on the screen. Starts a right-click. */ |
| 428 | @Override |
| 429 | public void onLongPress(MotionEvent e) { |
| 430 | if (e.getPointerCount() > 1) { |
| 431 | return; |
| 432 | } |
| 433 | |
| 434 | float x = e.getRawX(); |
| 435 | float y = e.getY(); |
| 436 | |
| 437 | Log.i("mouse", "Finger held down"); |
| 438 | if (mMousePressed) { |
| 439 | Log.i("mouse", "\tReleasing the currently-pressed button"); |
| 440 | handleMouseMovement(x, y, mMouseButton, false); |
| 441 | } |
| 442 | |
| 443 | Log.i("mouse", "\tStarting right click"); |
| 444 | mMouseButton = BUTTON_RIGHT; |
| 445 | mMousePressed = true; |
| 446 | handleMouseMovement(x, y, mMouseButton, mMousePressed); |
| 447 | } |
| 448 | } |
| 449 | } |