gecko/layout/generic/nsHTMLCanvasFrame.cpp
2010-08-13 22:01:58 +12:00

340 lines
11 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Vladimir Vukicevic <vladimir@pobox.com>
* Portions created by the Initial Developer are Copyright (C) 2004
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Vladimir Vukicevic <vladimir@pobox.com> (original author)
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* rendering object for the HTML <canvas> element */
#include "nsHTMLParts.h"
#include "nsCOMPtr.h"
#include "nsIServiceManager.h"
#include "nsGkAtoms.h"
#include "nsHTMLCanvasFrame.h"
#include "nsHTMLCanvasElement.h"
#include "nsDisplayList.h"
#include "nsLayoutUtils.h"
#include "nsTransform2D.h"
#include "gfxContext.h"
using namespace mozilla;
using namespace mozilla::layers;
static nsHTMLCanvasElement *
CanvasElementFromContent(nsIContent *content)
{
nsCOMPtr<nsIDOMHTMLCanvasElement> domCanvas(do_QueryInterface(content));
return domCanvas ? static_cast<nsHTMLCanvasElement*>(domCanvas.get()) : nsnull;
}
class nsDisplayCanvas : public nsDisplayItem {
public:
nsDisplayCanvas(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame)
{
MOZ_COUNT_CTOR(nsDisplayCanvas);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayCanvas() {
MOZ_COUNT_DTOR(nsDisplayCanvas);
}
#endif
NS_DISPLAY_DECL_NAME("nsDisplayCanvas", TYPE_CANVAS)
virtual PRBool IsOpaque(nsDisplayListBuilder* aBuilder) {
nsIFrame* f = GetUnderlyingFrame();
nsHTMLCanvasElement *canvas = CanvasElementFromContent(f->GetContent());
return canvas->GetIsOpaque();
}
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) {
nsHTMLCanvasFrame* f = static_cast<nsHTMLCanvasFrame*>(GetUnderlyingFrame());
return f->GetInnerArea() + ToReferenceFrame();
}
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager)
{
return static_cast<nsHTMLCanvasFrame*>(mFrame)->
BuildLayer(aBuilder, aManager, this);
}
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager)
{
// XXX we should have some kind of activity timeout here so that
// inactive canvases can be composited into the background
return mozilla::LAYER_ACTIVE;
}
};
nsIFrame*
NS_NewHTMLCanvasFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsHTMLCanvasFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsHTMLCanvasFrame)
nsHTMLCanvasFrame::~nsHTMLCanvasFrame()
{
}
nsIntSize
nsHTMLCanvasFrame::GetCanvasSize()
{
nsIntSize size(0,0);
nsHTMLCanvasElement *canvas = CanvasElementFromContent(GetContent());
if (canvas) {
size = canvas->GetSize();
} else {
NS_NOTREACHED("couldn't get canvas size");
}
return size;
}
/* virtual */ nscoord
nsHTMLCanvasFrame::GetMinWidth(nsIRenderingContext *aRenderingContext)
{
// XXX The caller doesn't account for constraints of the height,
// min-height, and max-height properties.
nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
DISPLAY_MIN_WIDTH(this, result);
return result;
}
/* virtual */ nscoord
nsHTMLCanvasFrame::GetPrefWidth(nsIRenderingContext *aRenderingContext)
{
// XXX The caller doesn't account for constraints of the height,
// min-height, and max-height properties.
nscoord result = nsPresContext::CSSPixelsToAppUnits(GetCanvasSize().width);
DISPLAY_PREF_WIDTH(this, result);
return result;
}
/* virtual */ nsSize
nsHTMLCanvasFrame::GetIntrinsicRatio()
{
nsIntSize size(GetCanvasSize());
return nsSize(nsPresContext::CSSPixelsToAppUnits(size.width),
nsPresContext::CSSPixelsToAppUnits(size.height));
}
/* virtual */ nsSize
nsHTMLCanvasFrame::ComputeSize(nsIRenderingContext *aRenderingContext,
nsSize aCBSize, nscoord aAvailableWidth,
nsSize aMargin, nsSize aBorder, nsSize aPadding,
PRBool aShrinkWrap)
{
nsIntSize size = GetCanvasSize();
IntrinsicSize intrinsicSize;
intrinsicSize.width.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.width));
intrinsicSize.height.SetCoordValue(nsPresContext::CSSPixelsToAppUnits(size.height));
nsSize intrinsicRatio = GetIntrinsicRatio(); // won't actually be used
return nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(
aRenderingContext, this,
intrinsicSize, intrinsicRatio, aCBSize,
aMargin, aBorder, aPadding);
}
NS_IMETHODIMP
nsHTMLCanvasFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aMetrics,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("nsHTMLCanvasFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aStatus);
NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
("enter nsHTMLCanvasFrame::Reflow: availSize=%d,%d",
aReflowState.availableWidth, aReflowState.availableHeight));
NS_PRECONDITION(mState & NS_FRAME_IN_REFLOW, "frame is not in reflow");
aStatus = NS_FRAME_COMPLETE;
aMetrics.width = aReflowState.ComputedWidth();
aMetrics.height = aReflowState.ComputedHeight();
// stash this away so we can compute our inner area later
mBorderPadding = aReflowState.mComputedBorderPadding;
aMetrics.width += mBorderPadding.left + mBorderPadding.right;
aMetrics.height += mBorderPadding.top + mBorderPadding.bottom;
if (GetPrevInFlow()) {
nscoord y = GetContinuationOffset(&aMetrics.width);
aMetrics.height -= y + mBorderPadding.top;
aMetrics.height = NS_MAX(0, aMetrics.height);
}
aMetrics.mOverflowArea.SetRect(0, 0, aMetrics.width, aMetrics.height);
FinishAndStoreOverflow(&aMetrics);
if (mRect.width != aMetrics.width || mRect.height != aMetrics.height) {
Invalidate(nsRect(0, 0, mRect.width, mRect.height));
}
NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
("exit nsHTMLCanvasFrame::Reflow: size=%d,%d",
aMetrics.width, aMetrics.height));
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aMetrics);
return NS_OK;
}
// FIXME taken from nsImageFrame, but then had splittable frame stuff
// removed. That needs to be fixed.
nsRect
nsHTMLCanvasFrame::GetInnerArea() const
{
nsRect r;
r.x = mBorderPadding.left;
r.y = mBorderPadding.top;
r.width = mRect.width - mBorderPadding.left - mBorderPadding.right;
r.height = mRect.height - mBorderPadding.top - mBorderPadding.bottom;
return r;
}
already_AddRefed<Layer>
nsHTMLCanvasFrame::BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
nsDisplayItem* aItem)
{
nsRect area = GetContentRect() - GetPosition() + aItem->ToReferenceFrame();
nsHTMLCanvasElement* element = static_cast<nsHTMLCanvasElement*>(GetContent());
nsIntSize canvasSize = GetCanvasSize();
if (canvasSize.width <= 0 || canvasSize.height <= 0 || area.IsEmpty())
return nsnull;
CanvasLayer* oldLayer = static_cast<CanvasLayer*>
(aBuilder->LayerBuilder()->GetLeafLayerFor(aBuilder, aManager, aItem));
nsRefPtr<CanvasLayer> layer = element->GetCanvasLayer(oldLayer, aManager);
if (!layer)
return nsnull;
element->MarkContextClean();
nsPresContext* presContext = PresContext();
gfxRect r = gfxRect(presContext->AppUnitsToGfxUnits(area.x),
presContext->AppUnitsToGfxUnits(area.y),
presContext->AppUnitsToGfxUnits(area.width),
presContext->AppUnitsToGfxUnits(area.height));
// Transform the canvas into the right place
gfxMatrix transform;
transform.Translate(r.pos);
transform.Scale(r.Width()/canvasSize.width, r.Height()/canvasSize.height);
layer->SetTransform(gfx3DMatrix::From2D(transform));
layer->SetFilter(nsLayoutUtils::GetGraphicsFilterForFrame(this));
return layer.forget();
}
NS_IMETHODIMP
nsHTMLCanvasFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
if (!IsVisibleForPainting(aBuilder))
return NS_OK;
nsresult rv = DisplayBorderBackgroundOutline(aBuilder, aLists);
NS_ENSURE_SUCCESS(rv, rv);
rv = aLists.Content()->AppendNewToTop(
new (aBuilder) nsDisplayCanvas(aBuilder, this));
NS_ENSURE_SUCCESS(rv, rv);
return DisplaySelectionOverlay(aBuilder, aLists,
nsISelectionDisplay::DISPLAY_IMAGES);
}
nsIAtom*
nsHTMLCanvasFrame::GetType() const
{
return nsGkAtoms::HTMLCanvasFrame;
}
// get the offset into the content area of the image where aImg starts if it is a continuation.
// from nsImageFrame
nscoord
nsHTMLCanvasFrame::GetContinuationOffset(nscoord* aWidth) const
{
nscoord offset = 0;
if (aWidth) {
*aWidth = 0;
}
if (GetPrevInFlow()) {
for (nsIFrame* prevInFlow = GetPrevInFlow() ; prevInFlow; prevInFlow = prevInFlow->GetPrevInFlow()) {
nsRect rect = prevInFlow->GetRect();
if (aWidth) {
*aWidth = rect.width;
}
offset += rect.height;
}
offset -= mBorderPadding.top;
offset = NS_MAX(0, offset);
}
return offset;
}
#ifdef ACCESSIBILITY
already_AddRefed<nsAccessible>
nsHTMLCanvasFrame::CreateAccessible()
{
return nsnull;
}
#endif
#ifdef DEBUG
NS_IMETHODIMP
nsHTMLCanvasFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("HTMLCanvas"), aResult);
}
#endif