DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (fce0b326cd31)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsView_h__
#define nsView_h__

#include "nsCoord.h"
#include "nsRect.h"
#include "nsPoint.h"
#include "nsRegion.h"
#include "nsCRT.h"
#include "nsCOMPtr.h"
#include "nsWidgetInitData.h"  // for nsWindowType
#include "nsIWidgetListener.h"
#include "Units.h"
#include "mozilla/Attributes.h"
#include "mozilla/EventForwards.h"

class nsViewManager;
class nsIWidget;
class nsIFrame;

namespace mozilla {
class PresShell;
}  // namespace mozilla

/**
 * nsView's serve two main purposes: 1) a bridge between nsIFrame's and
 * nsIWidget's, 2) linking the frame tree of a(n) (in-process) subdocument with
 * its parent document frame tree. Historically views were used for more things,
 * but their role has been reduced, and could be reduced to nothing in the
 * future (bug 337801 tracks removing views). Views are generally associated
 * with a frame. A view that does not have a frame is called an anonymous view.
 * Some frames also have associated widgets (think os level windows). If a frame
 * has a widget it must also have a view, but not all frames with views will
 * have widgets.
 *
 * Only five types of frames can have a view: root frames (ViewportFrame),
 * subdocument frames (nsSubDocumentFrame), plugin frames (nsPluginFrame),
 * menu popup frames (nsMenuPopupFrame), and list control frames
 * (nsListControlFrame). Root frames and subdocument frames have views to link
 * the two documents together (the frame trees do not link up otherwise).
 * Plugin frames, menu popup frames, and list control frames have views because
 * they (sometimes) need to create widgets (although plugins with widgets might
 * be going away/gone?). Menu popup frames handles xul popups, which is anything
 * where we need content to go over top the main window at an os level. List
 * control frames handle select popups/dropdowns in non-e10s mode.
 *
 * The term "root view" refers to the root view of a document. Just like root
 * frames, root views can have parent views. Only the root view of the root
 * document in the process will not have a parent.
 *
 * All views are created by their frames except root views. Root views are
 * special. Root views are created in nsDocumentViewer::MakeWindow before the
 * root frame is created, so the root view will not have a frame very early in
 * document creation.
 *
 * Subdocument frames and plugin frames have an anonymous (no frame associated
 * with it) inner view that is a child of their "outer" view. On a plugin frame
 * with a widget the inner view would be associated with the widget (as opposed
 * to the outer view).
 *
 * On a subdocument frame the inner view serves as the parent of the
 * root view of the subdocument. The outer and inner view of the subdocument
 * frame belong to the subdocument frame and hence to the parent document. The
 * root view of the subdocument belongs to the subdocument.
 * nsLayoutUtils::GetCrossDocParentFrame and nsPresContext::GetParentPresContext
 * depend on this view structure and are the main way that we traverse across
 * the document boundary in layout.
 *
 * When the load of a new document is started in the subdocument, the creation
 * of the new subdocument and destruction of the old subdocument are not
 * linked. (This creation and destruction is handled in nsDocumentViewer.cpp.)
 * This means that the old and new document will both exist at the same time
 * during the loading of the new document. During this period the inner view of
 * the subdocument parent will be the parent of two root views. This means that
 * during this period there is a choice for which subdocument we draw,
 * nsSubDocumentFrame::GetSubdocumentPresShellForPainting is what makes that
 * choice. Note that this might not be a totally free choice, ie there might be
 * hidden dependencies and bugs if the way we choose is changed.
 *
 * One thing that is special about the root view of a chrome window is that
 * instead of creating a widget for the view, they can "attach" to the
 * existing widget that was created by appshell code or something else. (see
 * nsDocumentViewer::ShouldAttachToTopLevel)
 */

// Enumerated type to indicate the visibility of a layer.
// hide - the layer is not shown.
// show - the layer is shown irrespective of the visibility of
//        the layer's parent.
enum nsViewVisibility {
  nsViewVisibility_kHide = 0,
  nsViewVisibility_kShow = 1
};

// Public view flags

// Indicates that the view is using auto z-indexing
#define NS_VIEW_FLAG_AUTO_ZINDEX 0x0004

// Indicates that the view is a floating view.
#define NS_VIEW_FLAG_FLOATING 0x0008

//----------------------------------------------------------------------

/**
 * View interface
 *
 * Views are NOT reference counted. Use the Destroy() member function to
 * destroy a view.
 *
 * The lifetime of the view hierarchy is bounded by the lifetime of the
 * view manager that owns the views.
 *
 * Most of the methods here are read-only. To set the corresponding properties
 * of a view, go through nsViewManager.
 */

class nsView final : public nsIWidgetListener {
 public:
  friend class nsViewManager;

  typedef mozilla::LayoutDeviceIntRect LayoutDeviceIntRect;
  typedef mozilla::LayoutDeviceIntRegion LayoutDeviceIntRegion;

  void operator delete(void* ptr) { ::operator delete(ptr); }

  /**
   * Get the view manager which "owns" the view.
   * This method might require some expensive traversal work in the future. If
   * you can get the view manager from somewhere else, do that instead.
   * @result the view manager
   */
  nsViewManager* GetViewManager() const { return mViewManager; }

  /**
   * Find the view for the given widget, if there is one.
   * @return the view the widget belongs to, or null if the widget doesn't
   * belong to any view.
   */
  static nsView* GetViewFor(nsIWidget* aWidget);

  /**
   * Destroy the view.
   *
   * The view destroys its child views, and destroys and releases its
   * widget (if it has one).
   *
   * Also informs the view manager that the view is destroyed by calling
   * SetRootView(NULL) if the view is the root view and calling RemoveChild()
   * otherwise.
   */
  void Destroy();

  /**
   * Called to get the position of a view.
   * The specified coordinates are relative to the parent view's origin, but
   * are in appunits of this.
   * This is the (0, 0) origin of the coordinate space established by this view.
   * @param x out parameter for x position
   * @param y out parameter for y position
   */
  nsPoint GetPosition() const {
    NS_ASSERTION(!IsRoot() || (mPosX == 0 && mPosY == 0),
                 "root views should always have explicit position of (0,0)");
    return nsPoint(mPosX, mPosY);
  }

  /**
   * Called to get the dimensions and position of the view's bounds.
   * The view's bounds (x,y) are relative to the origin of the parent view, but
   * are in appunits of this.
   * The view's bounds (x,y) might not be the same as the view's position,
   * if the view has content above or to the left of its origin.
   * @param aBounds out parameter for bounds
   */
  nsRect GetBounds() const { return mDimBounds; }

  /**
   * The bounds of this view relative to this view. So this is the same as
   * GetBounds except this is relative to this view instead of the parent view.
   */
  nsRect GetDimensions() const {
    nsRect r = mDimBounds;
    r.MoveBy(-mPosX, -mPosY);
    return r;
  }

  /**
   * Get the offset between the coordinate systems of |this| and aOther.
   * Adding the return value to a point in the coordinate system of |this|
   * will transform the point to the coordinate system of aOther.
   *
   * The offset is expressed in appunits of |this|. So if you are getting the
   * offset between views in different documents that might have different
   * appunits per devpixel ratios you need to be careful how you use the
   * result.
   *
   * If aOther is null, this will return the offset of |this| from the
   * root of the viewmanager tree.
   *
   * This function is fastest when aOther is an ancestor of |this|.
   *
   * NOTE: this actually returns the offset from aOther to |this|, but
   * that offset is added to transform _coordinates_ from |this| to aOther.
   */
  nsPoint GetOffsetTo(const nsView* aOther) const;

  /**
   * Get the offset between the origin of |this| and the origin of aWidget.
   * Adding the return value to a point in the coordinate system of |this|
   * will transform the point to the coordinate system of aWidget.
   *
   * The offset is expressed in appunits of |this|.
   */
  nsPoint GetOffsetToWidget(nsIWidget* aWidget) const;

  /**
   * Takes a point aPt that is in the coordinate system of |this|'s parent view
   * and converts it to be in the coordinate system of |this| taking into
   * account the offset and any app unit per dev pixel ratio differences.
   */
  nsPoint ConvertFromParentCoords(nsPoint aPt) const;

  /**
   * Called to query the visibility state of a view.
   * @result current visibility state
   */
  nsViewVisibility GetVisibility() const { return mVis; }

  /**
   * Get whether the view "floats" above all other views,
   * which tells the compositor not to consider higher views in
   * the view hierarchy that would geometrically intersect with
   * this view. This is a hack, but it fixes some problems with
   * views that need to be drawn in front of all other views.
   * @result true if the view floats, false otherwise.
   */
  bool GetFloating() const { return (mVFlags & NS_VIEW_FLAG_FLOATING) != 0; }

  /**
   * Called to query the parent of the view.
   * @result view's parent
   */
  nsView* GetParent() const { return mParent; }

  /**
   * The view's first child is the child which is earliest in document order.
   * @result first child
   */
  nsView* GetFirstChild() const { return mFirstChild; }

  /**
   * Called to query the next sibling of the view.
   * @result view's next sibling
   */
  nsView* GetNextSibling() const { return mNextSibling; }

  /**
   * Set the view's frame.
   */
  void SetFrame(nsIFrame* aRootFrame) { mFrame = aRootFrame; }

  /**
   * Retrieve the view's frame.
   */
  nsIFrame* GetFrame() const { return mFrame; }

  /**
   * Get the nearest widget in this view or a parent of this view and
   * the offset from the widget's origin to this view's origin
   * @param aOffset - if non-null the offset from this view's origin to the
   * widget's origin (usually positive) expressed in appunits of this will be
   * returned in aOffset.
   * @return the widget closest to this view; can be null because some view
   * trees don't have widgets at all (e.g., printing), but if any view in the
   * view tree has a widget, then it's safe to assume this will not return null
   */
  nsIWidget* GetNearestWidget(nsPoint* aOffset) const;

  /**
   * Create a widget to associate with this view.  This variant of
   * CreateWidget*() will look around in the view hierarchy for an
   * appropriate parent widget for the view.
   *
   * @param aWidgetInitData data used to initialize this view's widget before
   *        its create is called.
   * @return error status
   */
  nsresult CreateWidget(nsWidgetInitData* aWidgetInitData = nullptr,
                        bool aEnableDragDrop = true,
                        bool aResetVisibility = true);

  /**
   * Create a widget for this view with an explicit parent widget.
   * |aParentWidget| must be nonnull.  The other params are the same
   * as for |CreateWidget()|.
   */
  nsresult CreateWidgetForParent(nsIWidget* aParentWidget,
                                 nsWidgetInitData* aWidgetInitData = nullptr,
                                 bool aEnableDragDrop = true,
                                 bool aResetVisibility = true);

  /**
   * Create a popup widget for this view.  Pass |aParentWidget| to
   * explicitly set the popup's parent.  If it's not passed, the view
   * hierarchy will be searched for an appropriate parent widget.  The
   * other params are the same as for |CreateWidget()|, except that
   * |aWidgetInitData| must be nonnull.
   */
  nsresult CreateWidgetForPopup(nsWidgetInitData* aWidgetInitData,
                                nsIWidget* aParentWidget = nullptr,
                                bool aEnableDragDrop = true,
                                bool aResetVisibility = true);

  /**
   * Destroys the associated widget for this view.  If this method is
   * not called explicitly, the widget when be destroyed when its
   * view gets destroyed.
   */
  void DestroyWidget();

  /**
   * Attach/detach a top level widget from this view. When attached, the view
   * updates the widget's device context and allows the view to begin receiving
   * gecko events. The underlying base window associated with the widget will
   * continues to receive events it expects.
   *
   * An attached widget will not be destroyed when the view is destroyed,
   * allowing the recycling of a single top level widget over multiple views.
   *
   * @param aWidget The widget to attach to / detach from.
   */
  nsresult AttachToTopLevelWidget(nsIWidget* aWidget);
  nsresult DetachFromTopLevelWidget();

  /**
   * Returns a flag indicating whether the view owns it's widget
   * or is attached to an existing top level widget.
   */
  bool IsAttachedToTopLevel() const { return mWidgetIsTopLevel; }

  /**
   * In 4.0, the "cutout" nature of a view is queryable.
   * If we believe that all cutout view have a native widget, this
   * could be a replacement.
   * @param aWidget out parameter for widget that this view contains,
   *        or nullptr if there is none.
   */
  nsIWidget* GetWidget() const { return mWindow; }

  /**
   * The widget which we have attached a listener to can also have a "previous"
   * listener set on it. This is to keep track of the last nsView when
   * navigating to a new one so that we can continue to paint that if the new
   * one isn't ready yet.
   */
  void SetPreviousWidget(nsIWidget* aWidget) { mPreviousWindow = aWidget; }

  /**
   * Returns true if the view has a widget associated with it.
   */
  bool HasWidget() const { return mWindow != nullptr; }

  void SetForcedRepaint(bool aForceRepaint) { mForcedRepaint = aForceRepaint; }

  void SetNeedsWindowPropertiesSync();

  /**
   * Make aWidget direct its events to this view.
   * The caller must call DetachWidgetEventHandler before this view
   * is destroyed.
   */
  void AttachWidgetEventHandler(nsIWidget* aWidget);
  /**
   * Stop aWidget directing its events to this view.
   */
  void DetachWidgetEventHandler(nsIWidget* aWidget);

#ifdef DEBUG
  /**
   * Output debug info to FILE
   * @param out output file handle
   * @param aIndent indentation depth
   * NOTE: virtual so that debugging tools not linked into gklayout can access
   * it
   */
  virtual void List(FILE* out, int32_t aIndent = 0) const;
#endif  // DEBUG

  /**
   * @result true iff this is the root view for its view manager
   */
  bool IsRoot() const;

  LayoutDeviceIntRect CalcWidgetBounds(nsWindowType aType);

  // This is an app unit offset to add when converting view coordinates to
  // widget coordinates.  It is the offset in view coordinates from widget
  // origin (unlike views, widgets can't extend above or to the left of their
  // origin) to view origin expressed in appunits of this.
  nsPoint ViewToWidgetOffset() const { return mViewToWidgetOffset; }

  /**
   * Called to indicate that the position of the view has been changed.
   * The specified coordinates are in the parent view's coordinate space.
   * @param x new x position
   * @param y new y position
   */
  void SetPosition(nscoord aX, nscoord aY);

  /**
   * Called to indicate that the z-index of a view has been changed.
   * The z-index is relative to all siblings of the view.
   * @param aAuto Indicate that the z-index of a view is "auto". An "auto"
   *              z-index means that the view does not define a new stacking
   *              context, which means that the z-indicies of the view's
   *              children are relative to the view's siblings.
   * @param zindex new z depth
   */
  void SetZIndex(bool aAuto, int32_t aZIndex);
  bool GetZIndexIsAuto() const {
    return (mVFlags & NS_VIEW_FLAG_AUTO_ZINDEX) != 0;
  }
  int32_t GetZIndex() const { return mZIndex; }

  void SetParent(nsView* aParent) { mParent = aParent; }
  void SetNextSibling(nsView* aSibling) {
    NS_ASSERTION(aSibling != this, "Can't be our own sibling!");
    mNextSibling = aSibling;
  }

  nsRegion* GetDirtyRegion() {
    if (!mDirtyRegion) {
      NS_ASSERTION(!mParent || GetFloating(),
                   "Only display roots should have dirty regions");
      mDirtyRegion = new nsRegion();
      NS_ASSERTION(mDirtyRegion, "Out of memory!");
    }
    return mDirtyRegion;
  }

  // nsIWidgetListener
  virtual mozilla::PresShell* GetPresShell() override;
  virtual nsView* GetView() override { return this; }
  virtual bool WindowMoved(nsIWidget* aWidget, int32_t x, int32_t y) override;
  virtual bool WindowResized(nsIWidget* aWidget, int32_t aWidth,
                             int32_t aHeight) override;
  virtual bool RequestWindowClose(nsIWidget* aWidget) override;
  MOZ_CAN_RUN_SCRIPT_BOUNDARY
  virtual void WillPaintWindow(nsIWidget* aWidget) override;
  MOZ_CAN_RUN_SCRIPT_BOUNDARY
  virtual bool PaintWindow(nsIWidget* aWidget,
                           LayoutDeviceIntRegion aRegion) override;
  MOZ_CAN_RUN_SCRIPT_BOUNDARY
  virtual void DidPaintWindow() override;
  virtual void DidCompositeWindow(
      mozilla::layers::TransactionId aTransactionId,
      const mozilla::TimeStamp& aCompositeStart,
      const mozilla::TimeStamp& aCompositeEnd) override;
  virtual void RequestRepaint() override;
  virtual bool ShouldNotBeVisible() override;
  MOZ_CAN_RUN_SCRIPT_BOUNDARY
  virtual nsEventStatus HandleEvent(mozilla::WidgetGUIEvent* aEvent,
                                    bool aUseAttachedEvents) override;

  virtual ~nsView();

  nsPoint GetOffsetTo(const nsView* aOther, const int32_t aAPD) const;
  nsIWidget* GetNearestWidget(nsPoint* aOffset, const int32_t aAPD) const;

  bool IsPrimaryFramePaintSuppressed();

 private:
  explicit nsView(nsViewManager* aViewManager = nullptr,
                  nsViewVisibility aVisibility = nsViewVisibility_kShow);

  bool ForcedRepaint() { return mForcedRepaint; }

  // Do the actual work of ResetWidgetBounds, unconditionally.  Don't
  // call this method if we have no widget.
  void DoResetWidgetBounds(bool aMoveOnly, bool aInvalidateChangedSize);
  void InitializeWindow(bool aEnableDragDrop, bool aResetVisibility);

  bool IsEffectivelyVisible();

  /**
   * Called to indicate that the dimensions of the view have been changed.
   * The x and y coordinates may be < 0, indicating that the view extends above
   * or to the left of its origin position. The term 'dimensions' indicates it
   * is relative to this view.
   */
  void SetDimensions(const nsRect& aRect, bool aPaint = true,
                     bool aResizeWidget = true);

  /**
   * Called to indicate that the visibility of a view has been
   * changed.
   * @param visibility new visibility state
   */
  void SetVisibility(nsViewVisibility visibility);

  /**
   * Set/Get whether the view "floats" above all other views,
   * which tells the compositor not to consider higher views in
   * the view hierarchy that would geometrically intersect with
   * this view. This is a hack, but it fixes some problems with
   * views that need to be drawn in front of all other views.
   * @result true if the view floats, false otherwise.
   */
  void SetFloating(bool aFloatingView);

  // Helper function to get mouse grabbing off this view (by moving it to the
  // parent, if we can)
  void DropMouseGrabbing();

  // Same as GetBounds but converts to parent appunits if they are different.
  nsRect GetBoundsInParentUnits() const;

  bool HasNonEmptyDirtyRegion() {
    return mDirtyRegion && !mDirtyRegion->IsEmpty();
  }

  void InsertChild(nsView* aChild, nsView* aSibling);
  void RemoveChild(nsView* aChild);

  void ResetWidgetBounds(bool aRecurse, bool aForceSync);
  void AssertNoWindow();

  void NotifyEffectiveVisibilityChanged(bool aEffectivelyVisible);

  // Update the cached RootViewManager for all view manager descendents.
  void InvalidateHierarchy();

  nsViewManager* mViewManager;
  nsView* mParent;
  nsCOMPtr<nsIWidget> mWindow;
  nsCOMPtr<nsIWidget> mPreviousWindow;
  nsView* mNextSibling;
  nsView* mFirstChild;
  nsIFrame* mFrame;
  nsRegion* mDirtyRegion;
  int32_t mZIndex;
  nsViewVisibility mVis;
  // position relative our parent view origin but in our appunits
  nscoord mPosX, mPosY;
  // relative to parent, but in our appunits
  nsRect mDimBounds;
  // in our appunits
  nsPoint mViewToWidgetOffset;
  uint32_t mVFlags;
  bool mWidgetIsTopLevel;
  bool mForcedRepaint;
  bool mNeedsWindowPropertiesSync;
};

#endif