gecko/view/public/nsIView.h
2012-05-21 12:12:37 +01:00

425 lines
14 KiB
C++

/* -*- 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 nsIView_h___
#define nsIView_h___
#include "nsISupports.h"
#include "nsCoord.h"
#include "nsRect.h"
#include "nsPoint.h"
#include "nsNativeWidget.h"
#include "nsIWidget.h"
#include "nsWidgetInitData.h"
#include "nsIFrame.h"
class nsIViewManager;
class nsViewManager;
class nsView;
class nsWeakView;
class nsIWidget;
// 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
};
#define NS_IVIEW_IID \
{ 0x697948d2, 0x3f10, 0x407d, \
{ 0xb8, 0x94, 0x9f, 0x36, 0xd2, 0x11, 0xdb, 0xf1 } }
// 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
// If set it indicates that this view should be
// displayed above z-index:auto views if this view
// is z-index:auto also
#define NS_VIEW_FLAG_TOPMOST 0x0010
//----------------------------------------------------------------------
/**
* 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 nsIViewManager.
*/
class nsIView
{
public:
NS_DECLARE_STATIC_IID_ACCESSOR(NS_IVIEW_IID)
/**
* 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 nsIView* GetViewFor(nsIWidget* aWidget);
/**
* 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
*/
nsIViewManager* GetViewManager() const
{ return reinterpret_cast<nsIViewManager*>(mViewManager); }
/**
* 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 {
// Call ExternalIsRoot here so that we can get to it from other
// components
NS_ASSERTION(!ExternalIsRoot() || (mPosX == 0 && mPosY == 0),
"root views should always have explicit position of (0,0)");
return nsPoint(mPosX, mPosY);
}
/**
* Set the position of a view. This does not cause any invalidation. It
* does reposition any widgets in this view or its descendants.
*/
virtual void SetPosition(nscoord aX, nscoord aY) = 0;
/**
* 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 nsIView* 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
*/
nsIView* GetParent() const { return reinterpret_cast<nsIView*>(mParent); }
/**
* The view's first child is the child which is earliest in document order.
* @result first child
*/
nsIView* GetFirstChild() const { return reinterpret_cast<nsIView*>(mFirstChild); }
/**
* Called to query the next sibling of the view.
* @result view's next sibling
*/
nsIView* GetNextSibling() const { return reinterpret_cast<nsIView*>(mNextSibling); }
void SetNextSibling(nsIView *aSibling) {
mNextSibling = reinterpret_cast<nsView*>(aSibling);
}
/**
* 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
* XXX Remove this 'virtual' when gfx+widget are merged into gklayout;
* Mac widget depends on this method, which is BOGUS!
*/
virtual 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 = nsnull,
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 = nsnull,
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 = nsnull,
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 nsnull if there is none.
*/
nsIWidget* GetWidget() const { return mWindow; }
/**
* Returns true if the view has a widget associated with it.
*/
bool HasWidget() const { return mWindow != nsnull; }
/**
* Make aWidget direct its events to this view.
* The caller must call DetachWidgetEventHandler before this view
* is destroyed.
*/
EVENT_CALLBACK 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, PRInt32 aIndent = 0) const;
#endif // DEBUG
/**
* @result true iff this is the root view for its view manager
*/
bool IsRoot() const;
virtual bool ExternalIsRoot() const;
void SetDeletionObserver(nsWeakView* aDeletionObserver);
nsIntRect CalcWidgetBounds(nsWindowType aType);
bool IsEffectivelyVisible();
// 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; }
protected:
friend class nsWeakView;
nsViewManager *mViewManager;
nsView *mParent;
nsIWidget *mWindow;
nsView *mNextSibling;
nsView *mFirstChild;
nsIFrame *mFrame;
PRInt32 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;
float mOpacity;
PRUint32 mVFlags;
nsWeakView* mDeletionObserver;
bool mWidgetIsTopLevel;
virtual ~nsIView() {}
private:
nsView* Impl();
const nsView* Impl() const;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsIView, NS_IVIEW_IID)
// nsWeakViews must *not* be used in heap!
class nsWeakView
{
public:
nsWeakView(nsIView* aView) : mPrev(nsnull), mView(aView)
{
if (mView) {
mView->SetDeletionObserver(this);
}
}
~nsWeakView()
{
if (mView) {
NS_ASSERTION(mView->mDeletionObserver == this,
"nsWeakViews deleted in wrong order!");
// Clear deletion observer temporarily.
mView->SetDeletionObserver(nsnull);
// Put back the previous deletion observer.
mView->SetDeletionObserver(mPrev);
}
}
bool IsAlive() { return !!mView; }
nsIView* GetView() { return mView; }
void SetPrevious(nsWeakView* aWeakView) { mPrev = aWeakView; }
void Clear()
{
if (mPrev) {
mPrev->Clear();
}
mView = nsnull;
}
private:
static void* operator new(size_t) CPP_THROW_NEW { return 0; }
static void operator delete(void*, size_t) {}
nsWeakView* mPrev;
nsIView* mView;
};
#endif