gecko-dev/dom/canvas/nsICanvasRenderingContextIn...

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/* -*- Mode: C++; tab-width: 40; 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 nsICanvasRenderingContextInternal_h___
#define nsICanvasRenderingContextInternal_h___
#include "mozilla/gfx/2D.h"
#include "nsISupports.h"
#include "nsIInputStream.h"
#include "nsIDocShell.h"
#include "nsRefreshDriver.h"
#include "mozilla/dom/HTMLCanvasElement.h"
#include "GraphicsFilter.h"
#include "mozilla/RefPtr.h"
#define NS_ICANVASRENDERINGCONTEXTINTERNAL_IID \
{ 0x3cc9e801, 0x1806, 0x4ff6, \
{ 0x86, 0x14, 0xf9, 0xd0, 0xf4, 0xfb, 0x3b, 0x08 } }
class gfxASurface;
class nsDisplayListBuilder;
namespace mozilla {
namespace layers {
class CanvasLayer;
class LayerManager;
} // namespace layers
namespace gfx {
class SourceSurface;
} // namespace gfx
} // namespace mozilla
class nsICanvasRenderingContextInternal :
public nsISupports,
public nsAPostRefreshObserver
{
public:
typedef mozilla::layers::CanvasLayer CanvasLayer;
typedef mozilla::layers::LayerManager LayerManager;
NS_DECLARE_STATIC_IID_ACCESSOR(NS_ICANVASRENDERINGCONTEXTINTERNAL_IID)
void SetCanvasElement(mozilla::dom::HTMLCanvasElement* parentCanvas)
{
RemovePostRefreshObserver();
mCanvasElement = parentCanvas;
AddPostRefreshObserverIfNecessary();
}
virtual nsIPresShell *GetPresShell() {
if (mCanvasElement) {
return mCanvasElement->OwnerDoc()->GetShell();
}
return nullptr;
}
void RemovePostRefreshObserver()
{
if (mRefreshDriver) {
mRefreshDriver->RemovePostRefreshObserver(this);
mRefreshDriver = nullptr;
}
}
void AddPostRefreshObserverIfNecessary()
{
if (!GetPresShell() ||
!GetPresShell()->GetPresContext() ||
!GetPresShell()->GetPresContext()->RefreshDriver()) {
return;
}
mRefreshDriver = GetPresShell()->GetPresContext()->RefreshDriver();
mRefreshDriver->AddPostRefreshObserver(this);
}
mozilla::dom::HTMLCanvasElement* GetParentObject() const
{
return mCanvasElement;
}
#ifdef DEBUG
// Useful for testing
virtual int32_t GetWidth() const = 0;
virtual int32_t GetHeight() const = 0;
#endif
// Sets the dimensions of the canvas, in pixels. Called
// whenever the size of the element changes.
NS_IMETHOD SetDimensions(int32_t width, int32_t height) = 0;
NS_IMETHOD InitializeWithSurface(nsIDocShell *docShell, gfxASurface *surface, int32_t width, int32_t height) = 0;
// Creates an image buffer. Returns null on failure.
virtual void GetImageBuffer(uint8_t** imageBuffer, int32_t* format) = 0;
// Gives you a stream containing the image represented by this context.
// The format is given in mimeTime, for example "image/png".
//
// If the image format does not support transparency or includeTransparency
// is false, alpha will be discarded and the result will be the image
// composited on black.
NS_IMETHOD GetInputStream(const char *mimeType,
const char16_t *encoderOptions,
nsIInputStream **stream) = 0;
// This gets an Azure SourceSurface for the canvas, this will be a snapshot
// of the canvas at the time it was called.
// If premultAlpha is provided, then it assumed the callee can handle
// un-premultiplied surfaces, and *premultAlpha will be set to false
// if one is returned.
virtual already_AddRefed<mozilla::gfx::SourceSurface> GetSurfaceSnapshot(bool* premultAlpha = nullptr) = 0;
// If this context is opaque, the backing store of the canvas should
// be created as opaque; all compositing operators should assume the
// dst alpha is always 1.0. If this is never called, the context
// defaults to false (not opaque).
NS_IMETHOD SetIsOpaque(bool isOpaque) = 0;
virtual bool GetIsOpaque() = 0;
// Invalidate this context and release any held resources, in preperation
// for possibly reinitializing with SetDimensions/InitializeWithSurface.
NS_IMETHOD Reset() = 0;
// Return the CanvasLayer for this context, creating
// one for the given layer manager if not available.
virtual already_AddRefed<CanvasLayer> GetCanvasLayer(nsDisplayListBuilder* builder,
CanvasLayer *oldLayer,
LayerManager *manager) = 0;
// Return true if the canvas should be forced to be "inactive" to ensure
// it can be drawn to the screen even if it's too large to be blitted by
// an accelerated CanvasLayer.
virtual bool ShouldForceInactiveLayer(LayerManager *manager) { return false; }
virtual void MarkContextClean() = 0;
// Redraw the dirty rectangle of this canvas.
NS_IMETHOD Redraw(const gfxRect &dirty) = 0;
NS_IMETHOD SetContextOptions(JSContext* cx, JS::Handle<JS::Value> options) { return NS_OK; }
// return true and fills in the bounding rect if elementis a child and has a hit region.
virtual bool GetHitRegionRect(mozilla::dom::Element* element, nsRect& rect) { return false; }
// Given a point, return hit region ID if it exists or an empty string if it doesn't
virtual nsString GetHitRegion(const mozilla::gfx::Point& point) { return nsString(); }
//
// shmem support
//
// If this context can be set to use Mozilla's Shmem segments as its backing
// store, this will set it to that state. Note that if you have drawn
// anything into this canvas before changing the shmem state, it will be
// lost.
NS_IMETHOD SetIsIPC(bool isIPC) = 0;
protected:
nsRefPtr<mozilla::dom::HTMLCanvasElement> mCanvasElement;
nsRefPtr<nsRefreshDriver> mRefreshDriver;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsICanvasRenderingContextInternal,
NS_ICANVASRENDERINGCONTEXTINTERNAL_IID)
#endif /* nsICanvasRenderingContextInternal_h___ */