/* -*- 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/EventForwards.h"

class nsViewManager;

class nsIWidget;

class nsIFrame;

// 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 nsIPresShell* 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;

  virtual void WillPaintWindow(nsIWidget* aWidget) override;

  virtual bool PaintWindow(nsIWidget* aWidget,

                           LayoutDeviceIntRegion aRegion) override;

  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 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