Mozilla/mozilla/layout/mathml/base/src/nsMathMLmsqrtFrame.cpp

225 lines
7.3 KiB
C++

/*
* 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 MathML Project.
*
* The Initial Developer of the Original Code is The University Of
* Queensland. Portions created by The University Of Queensland are
* Copyright (C) 1999 The University Of Queensland. All Rights Reserved.
*
* Contributor(s):
* Roger B. Sidje <rbs@maths.uq.edu.au>
* David J. Fiddes <D.J.Fiddes@hw.ac.uk>
* Vilya Harvey <vilya@nag.co.uk>
*/
#include "nsCOMPtr.h"
#include "nsHTMLParts.h"
#include "nsIHTMLContent.h"
#include "nsFrame.h"
#include "nsLineLayout.h"
#include "nsHTMLIIDs.h"
#include "nsIPresContext.h"
#include "nsHTMLAtoms.h"
#include "nsUnitConversion.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsINameSpaceManager.h"
#include "nsIRenderingContext.h"
#include "nsIFontMetrics.h"
#include "nsStyleUtil.h"
#include "nsMathMLmsqrtFrame.h"
//
// <msqrt> and <mroot> -- form a radical - implementation
//
nsresult
NS_NewMathMLmsqrtFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame)
{
NS_PRECONDITION(aNewFrame, "null OUT ptr");
if (nsnull == aNewFrame) {
return NS_ERROR_NULL_POINTER;
}
nsMathMLmsqrtFrame* it = new (aPresShell) nsMathMLmsqrtFrame;
if (nsnull == it) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aNewFrame = it;
return NS_OK;
}
nsMathMLmsqrtFrame::nsMathMLmsqrtFrame() :
mSqrChar(),
mBarChar()
{
mSqrChar.SetEnum(eMathMLChar_Sqrt);
mBarChar.SetEnum(eMathMLChar_OverBar);
}
nsMathMLmsqrtFrame::~nsMathMLmsqrtFrame()
{
}
NS_IMETHODIMP
nsMathMLmsqrtFrame::Init(nsIPresContext* aPresContext,
nsIContent* aContent,
nsIFrame* aParent,
nsIStyleContext* aContext,
nsIFrame* aPrevInFlow)
{
nsresult rv = NS_OK;
rv = nsMathMLContainerFrame::Init(aPresContext, aContent, aParent,
aContext, aPrevInFlow);
mEmbellishData.flags = NS_MATHML_STRETCH_ALL_CHILDREN;
// TODO: other attributes...
return rv;
}
NS_IMETHODIMP
nsMathMLmsqrtFrame::Paint(nsIPresContext* aPresContext,
nsIRenderingContext& aRenderingContext,
const nsRect& aDirtyRect,
nsFramePaintLayer aWhichLayer)
{
nsresult rv = NS_OK;
/////////////
// paint the content we are square-rooting
rv = nsMathMLContainerFrame::Paint(aPresContext, aRenderingContext,
aDirtyRect, aWhichLayer);
if (NS_SUCCEEDED(rv) && NS_FRAME_PAINT_LAYER_FOREGROUND == aWhichLayer) {
// paint the sqrt symbol
rv = mSqrChar.Paint(aPresContext, aRenderingContext, mStyleContext);
// paint the overline bar
rv = mBarChar.Paint(aPresContext, aRenderingContext, mStyleContext);
}
return rv;
}
NS_IMETHODIMP
nsMathMLmsqrtFrame::Reflow(nsIPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
nsresult rv = NS_OK;
///////////////
// Let the base class format our content like an inferred mrow
rv = nsMathMLContainerFrame::Reflow(aPresContext, aDesiredSize,
aReflowState, aStatus);
NS_ASSERTION(NS_FRAME_IS_COMPLETE(aStatus), "bad status");
if (NS_FAILED(rv)) {
return rv;
}
nscoord oldAscent = aDesiredSize.ascent;
////////////
// Prepare the radical symbol and the overline bar
nsIRenderingContext& renderingContext = *aReflowState.rendContext;
nsStyleFont font;
mStyleContext->GetStyle(eStyleStruct_Font, font);
renderingContext.SetFont(font.mFont);
// grab some metrics that will help to adjust the placements
nsCOMPtr<nsIFontMetrics> fm;
nscoord fontAscent, fontDescent;
renderingContext.GetFontMetrics(*getter_AddRefs(fm));
fm->GetMaxAscent(fontAscent);
fm->GetMaxDescent(fontDescent);
float p2t;
aPresContext->GetScaledPixelsToTwips(&p2t);
nscoord onePixel = NSIntPixelsToTwips(1, p2t);
nsBoundingMetrics bmSqr, bmBar;
nscoord dx, dy;
// radical symbol
renderingContext.GetBoundingMetrics(mSqrChar.GetUnicode(), PRUint32(1), bmSqr);
nscoord charWidth = bmSqr.width; // width of the radical symbol
// overline bar
renderingContext.GetBoundingMetrics(mBarChar.GetUnicode(), PRUint32(1), bmBar);
nscoord thickspace = bmBar.ascent + bmBar.descent; // height of the overline bar
// Stretch the sqrt symbol to the appropriate height if it is not big enough.
nsStretchMetrics contSize(aDesiredSize);
nsStretchMetrics desSize(fontDescent, fontAscent, charWidth, fontAscent + fontDescent);
mSqrChar.Stretch(aPresContext, renderingContext, mStyleContext,
NS_STRETCH_DIRECTION_VERTICAL, contSize, desSize);
charWidth = desSize.width;
if (aDesiredSize.ascent < desSize.ascent) {
aDesiredSize.ascent = desSize.ascent;
}
if (aDesiredSize.descent < desSize.descent) {
aDesiredSize.descent = desSize.descent;
}
aDesiredSize.height = aDesiredSize.ascent + aDesiredSize.descent;
dx = 0;
dy = 2*onePixel + (bmSqr.ascent - fontAscent);
mSqrChar.SetRect(nsRect(dx, dy, desSize.width, aDesiredSize.height));
dx = bmSqr.rightBearing;
// Stretch the overline bar to the appropriate width if it is not big enough.
contSize = nsStretchMetrics(aDesiredSize);
desSize = nsStretchMetrics(fontDescent, fontAscent, bmBar.rightBearing-bmBar.leftBearing, fontAscent + fontDescent);
nsStretchMetrics oldSize = desSize;
mBarChar.Stretch(aPresContext, renderingContext, mStyleContext,
NS_STRETCH_DIRECTION_HORIZONTAL, contSize, desSize);
dy = 2*onePixel + (bmBar.ascent - fontAscent);
if (oldSize == desSize) { // hasn't changed size! Char will be painted as a normal char
dx -= bmBar.leftBearing; // adjust so that it coincides with the sqrt char
// XXX need also to check when a single glyph wil be used
}
mBarChar.SetRect(nsRect(dx, dy, desSize.width, 2*onePixel + thickspace));
// Update the size of the container
aDesiredSize.width += charWidth;
aDesiredSize.ascent += 2*onePixel + thickspace;
aDesiredSize.height = aDesiredSize.ascent + aDesiredSize.descent;
//////////////////
// Adjust the origins to leave room for the sqrt char and the overline bar
nsRect rect;
dx = charWidth;
dy = aDesiredSize.ascent - oldAscent;
nsIFrame* childFrame = mFrames.FirstChild();
while (nsnull != childFrame) {
if (!IsOnlyWhitespace(childFrame)) {
childFrame->GetRect(rect);
childFrame->MoveTo(aPresContext, dx, rect.y + dy);
dx += rect.width;
}
rv = childFrame->GetNextSibling(&childFrame);
NS_ASSERTION(NS_SUCCEEDED(rv),"failed to get next child");
}
if (nsnull != aDesiredSize.maxElementSize) {
aDesiredSize.maxElementSize->width = aDesiredSize.width;
aDesiredSize.maxElementSize->height = aDesiredSize.height;
}
aStatus = NS_FRAME_COMPLETE;
return NS_OK;
}