gecko-dev/layout/generic/nsHTMLCanvasFrame.cpp

305 lines
9.5 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 "nsLayoutAtoms.h"
#include "nsHTMLCanvasFrame.h"
#include "nsICanvasElement.h"
#include "nsDisplayList.h"
#include "nsTransform2D.h"
nsIFrame*
NS_NewHTMLCanvasFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsHTMLCanvasFrame(aContext);
}
nsHTMLCanvasFrame::~nsHTMLCanvasFrame()
{
}
// We really want a PR_MINMAX to go along with PR_MIN/PR_MAX
#define MINMAX(_value,_min,_max) \
((_value) < (_min) \
? (_min) \
: ((_value) > (_max) \
? (_max) \
: (_value)))
NS_IMETHODIMP
nsHTMLCanvasFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aMetrics,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("nsHTMLCanvasFrame", aReflowState.reason);
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;
nsCOMPtr<nsICanvasElement> canvas(do_QueryInterface(GetContent()));
NS_ENSURE_TRUE(canvas, NS_ERROR_FAILURE);
PRUint32 w, h;
nsresult rv = canvas->GetSize (&w, &h);
NS_ENSURE_SUCCESS(rv, rv);
float p2t = GetPresContext()->PixelsToTwips();
mCanvasSize.SizeTo(NSIntPixelsToTwips(w, p2t), NSIntPixelsToTwips(h, p2t));
if (aReflowState.mComputedWidth == NS_INTRINSICSIZE)
aMetrics.width = mCanvasSize.width;
else
aMetrics.width = aReflowState.mComputedWidth;
if (aReflowState.mComputedHeight == NS_INTRINSICSIZE)
aMetrics.height = mCanvasSize.height;
else
aMetrics.height = aReflowState.mComputedHeight;
// clamp
aMetrics.height = MINMAX(aMetrics.height, aReflowState.mComputedMinHeight, aReflowState.mComputedMaxHeight);
aMetrics.width = MINMAX(aMetrics.width, aReflowState.mComputedMinWidth, aReflowState.mComputedMaxWidth);
// 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 = PR_MAX(0, aMetrics.height);
}
aMetrics.ascent = aMetrics.height;
aMetrics.descent = 0;
if (aMetrics.mComputeMEW) {
aMetrics.SetMEWToActualWidth(aReflowState.mStylePosition->mWidth.GetUnit());
}
if (aMetrics.mFlags & NS_REFLOW_CALC_MAX_WIDTH) {
aMetrics.mMaximumWidth = aMetrics.width;
}
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), PR_FALSE);
}
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;
}
void
nsHTMLCanvasFrame::PaintCanvas(nsIRenderingContext& aRenderingContext,
const nsRect& aDirtyRect, nsPoint aPt)
{
nsRect inner = GetInnerArea() + aPt;
nsCOMPtr<nsICanvasElement> canvas(do_QueryInterface(GetContent()));
if (!canvas)
return;
float t2p = GetPresContext()->TwipsToPixels();
float p2t = GetPresContext()->PixelsToTwips();
// XXXvlad clip to aDirtyRect!
if (inner.width != mCanvasSize.width ||
inner.height != mCanvasSize.height)
{
float sx = inner.width / (float) mCanvasSize.width;
float sy = inner.height / (float) mCanvasSize.height;
aRenderingContext.PushState();
aRenderingContext.Translate(inner.x, inner.y);
aRenderingContext.Scale(sx, sy);
canvas->RenderContexts(&aRenderingContext);
aRenderingContext.PopState();
} else {
//nsIRenderingContext::AutoPushTranslation(&aRenderingContext, px, py);
aRenderingContext.PushState();
aRenderingContext.Translate(inner.x, inner.y);
canvas->RenderContexts(&aRenderingContext);
aRenderingContext.PopState();
}
}
static void PaintCanvas(nsIFrame* aFrame, nsIRenderingContext* aCtx,
const nsRect& aDirtyRect, nsPoint aPt)
{
NS_STATIC_CAST(nsHTMLCanvasFrame*, aFrame)->PaintCanvas(*aCtx, aDirtyRect, aPt);
}
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)
nsDisplayGeneric(this, ::PaintCanvas, "Canvas"));
NS_ENSURE_SUCCESS(rv, rv);
return DisplaySelectionOverlay(aBuilder, aLists,
nsISelectionDisplay::DISPLAY_IMAGES);
}
NS_IMETHODIMP
nsHTMLCanvasFrame::CanContinueTextRun(PRBool& aContinueTextRun) const
{
// stolen from nsImageFrame.cpp
// images really CAN continue text runs, but the textFrame needs to be
// educated before we can indicate that it can. For now, we handle the fixing up
// of max element widths in nsLineLayout::VerticalAlignFrames, but hopefully
// this can be eliminated and the textFrame can be convinced to handle inlines
// that take up space in text runs.
aContinueTextRun = PR_FALSE;
return NS_OK;
}
NS_IMETHODIMP
nsHTMLCanvasFrame::GetContentForEvent(nsPresContext* aPresContext,
nsEvent* aEvent,
nsIContent** aContent)
{
NS_ENSURE_ARG_POINTER(aContent);
*aContent = GetContent();
NS_IF_ADDREF(*aContent);
return NS_OK;
}
nsIAtom*
nsHTMLCanvasFrame::GetType() const
{
return nsLayoutAtoms::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 = PR_MAX(0, offset);
}
return offset;
}
#ifdef ACCESSIBILITY
NS_IMETHODIMP
nsHTMLCanvasFrame::GetAccessible(nsIAccessible** aAccessible)
{
return NS_ERROR_FAILURE;
}
#endif
#ifdef DEBUG
NS_IMETHODIMP
nsHTMLCanvasFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("HTMLCanvas"), aResult);
}
NS_IMETHODIMP
nsHTMLCanvasFrame::List(FILE* out, PRInt32 aIndent) const
{
IndentBy(out, aIndent);
ListTag(out);
fputs("\n", out);
return NS_OK;
}
#endif