Mozilla/mozilla/layout/mathml/base/src/nsMathMLContainerFrame.cpp
rbs%maths.uq.edu.au cdfb86c649 Catching up with recent changes of the nsIFrame API
git-svn-id: svn://10.0.0.236/trunk@52136 18797224-902f-48f8-a5cc-f745e15eee43
1999-10-28 22:30:28 +00:00

499 lines
18 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>
*/
#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 "nsITextContent.h"
#include "nsMathMLAtoms.h"
#include "nsMathMLParts.h"
#include "nsMathMLChar.h"
#include "nsMathMLContainerFrame.h"
//
// nsMathMLContainerFrame implementation
//
// TODO: Proper management of ignorable whitespace
// and handling of non-math related frames.
// * Should math markups only enclose other math markups?
// Why bother... we can leave them in, as hinted in the newsgroup.
//
// * Space doesn't count. Handling space is more complicated than it seems.
// We have to clean inside and outside:
// <mi> a </mi> <mo> + </mo> <mi> b </mi>
// ^ ^ ^ ^ ^ ^ ^ ^
// *Outside* currently handled using IsOnlyWhitespace().
// For whitespace only frames, their rect is set zero.
//
// *Inside* not currently handled... so the user must do <mi>a</mi>
// What to do?!
// - Add a nsTextFrame::CompressWhitespace() *if* it is MathML content?!
// - via CSS property? Support for "none/compress"? (white-space: normal | pre | nowrap)
// nsISupports
// =============================================================================
NS_IMETHODIMP
nsMathMLContainerFrame::QueryInterface(REFNSIID aIID, void** aInstancePtr)
{
if (NULL == aInstancePtr) {
return NS_ERROR_NULL_POINTER;
}
*aInstancePtr = nsnull;
if (aIID.Equals(kIMathMLFrameIID)) {
*aInstancePtr = (void*)(nsIMathMLFrame*)this;
NS_ADDREF_THIS(); // not effectual, frames are not Refcounted
return NS_OK;
}
return nsHTMLContainerFrame::QueryInterface(aIID, aInstancePtr);
}
NS_IMETHODIMP_(nsrefcnt)
nsMathMLContainerFrame::AddRef(void)
{
return NS_OK;
}
NS_IMETHODIMP_(nsrefcnt)
nsMathMLContainerFrame::Release(void)
{
return NS_OK;
}
/* ///////////////
* MathML specific - Whitespace management ...
* WHITESPACE: don't forget that whitespace doesn't count in MathML!
* empty frames shouldn't be created in MathML, oh well that's another story.
* =============================================================================
*/
PRBool
nsMathMLContainerFrame::IsOnlyWhitespace(nsIFrame* aFrame)
{
NS_PRECONDITION(aFrame, "null arg");
PRBool rv = PR_FALSE;
// by empty frame we mean a leaf frame whose text content is empty...
nsCOMPtr<nsIContent> aContent;
aFrame->GetContent(getter_AddRefs(aContent));
if (nsnull == aContent)
return PR_TRUE;
PRInt32 numKids;
aContent->ChildCount(numKids);
if (0 == numKids) {
nsCOMPtr<nsITextContent> tc(do_QueryInterface(aContent));
if (tc.get()) tc->IsOnlyWhitespace(&rv);
}
return rv;
}
void
nsMathMLContainerFrame::ReflowEmptyChild(nsIPresContext& aPresContext,
nsIFrame* aFrame)
{
// nsHTMLReflowMetrics emptySize(nsnull);
// nsHTMLReflowState emptyReflowState(aPresContext, aReflowState, aFrame, nsSize(0,0));
// nsresult rv = ReflowChild(aFrame, aPresContext, emptySize, emptyReflowState, aStatus);
// 0-size the frame
aFrame->SetRect(&aPresContext, nsRect(0,0,0,0));
// 0-size the view, if any
nsIView* view = nsnull;
aFrame->GetView(&aPresContext, &view);
if (view) {
nsCOMPtr<nsIViewManager> vm;
view->GetViewManager(*getter_AddRefs(vm));
vm->ResizeView(view, 0,0);
}
}
/* /////////////
* nsIMathMLFrame - support methods for stretchy elements and scripting
* elements (nested frames within msub, msup, msubsup, munder, mover,
* munderover, mmultiscripts, mfrac, mroot, mtable).
* =============================================================================
*/
NS_IMETHODIMP
nsMathMLContainerFrame::Stretch(nsIPresContext& aPresContext,
nsStretchDirection aStretchDirection,
nsCharMetrics& aContainerSize,
nsCharMetrics& aDesiredStretchSize)
{
return NS_OK; // the Stretch() is only implemented by <mo> and its nsMathMLChar
}
NS_IMETHODIMP
nsMathMLContainerFrame::GetPresentationData(PRInt32* aScriptLevel,
PRBool* aDisplayStyle)
{
NS_PRECONDITION(aScriptLevel && aDisplayStyle, "null arg");
*aScriptLevel = mScriptLevel;
*aDisplayStyle = mDisplayStyle;
return NS_OK;
}
NS_IMETHODIMP
nsMathMLContainerFrame::UpdatePresentationData(PRInt32 aScriptLevelIncrement,
PRBool aDisplayStyle)
{
mScriptLevel += aScriptLevelIncrement;
mDisplayStyle = aDisplayStyle;
return NS_OK;
}
NS_IMETHODIMP
nsMathMLContainerFrame::UpdatePresentationDataFromChildAt(PRInt32 aIndex,
PRInt32 aScriptLevelIncrement,
PRBool aDisplayStyle)
{
nsIFrame* childFrame = mFrames.FirstChild();
while (nsnull != childFrame) {
if (!IsOnlyWhitespace(childFrame)) {
if (0 >= aIndex--) {
nsIMathMLFrame* aMathMLFrame = nsnull;
nsresult rv = childFrame->QueryInterface(nsIMathMLFrame::GetIID(), (void**)&aMathMLFrame);
if (NS_SUCCEEDED(rv) && nsnull != aMathMLFrame) {
// update
aMathMLFrame->UpdatePresentationData(aScriptLevelIncrement, aDisplayStyle);
// propagate down the subtrees
aMathMLFrame->UpdatePresentationDataFromChildAt(0, aScriptLevelIncrement, aDisplayStyle);
}
}
}
childFrame->GetNextSibling(&childFrame);
}
return NS_OK;
}
// helper method to alter the style context
// This method is used for switching the font to a subscript/superscript font in
// mfrac, msub, msup, msubsup, munder, mover, munderover, mmultiscripts
NS_IMETHODIMP
nsMathMLContainerFrame::InsertScriptLevelStyleContext(nsIPresContext& aPresContext)
{
nsresult rv = NS_OK;
nsIFrame* nextFrame = mFrames.FirstChild();
while (nsnull != nextFrame && NS_SUCCEEDED(rv)) {
nsIFrame* childFrame = nextFrame;
rv = nextFrame->GetNextSibling(&nextFrame);
if (!IsOnlyWhitespace(childFrame) && NS_SUCCEEDED(rv)) {
// see if the child frame implements the nsIMathMLFrame interface
nsIMathMLFrame* aMathMLFrame;
rv = childFrame->QueryInterface(nsIMathMLFrame::GetIID(), (void**)&aMathMLFrame);
if (nsnull != aMathMLFrame && NS_SUCCEEDED(rv)) {
// get the scriptlevel of the child
PRInt32 childLevel;
PRBool childDisplayStyle;
aMathMLFrame->GetPresentationData(&childLevel, &childDisplayStyle);
// Iteration to set a style context for the script level font.
// Wow, here is what is happening: the style system requires that any style context
// *must* be uniquely associated to a frame. So we insert as many frames as needed
// to scale-down (or scale-up) the fontsize.
PRInt32 gap = childLevel - mScriptLevel;
if (0 != gap) {
nsCOMPtr<nsIContent> childContent;
childFrame->GetContent(getter_AddRefs(childContent));
nsIFrame* firstFrame = nsnull;
nsIFrame* lastFrame = this;
nsIStyleContext* lastStyleContext = mStyleContext;
nsCOMPtr<nsIStyleContext> newStyleContext;
nsAutoString fontSize = (0 < gap)
? ":-moz-math-font-size-smaller"
: ":-moz-math-font-size-larger";
nsCOMPtr<nsIAtom> fontAtom(getter_AddRefs(NS_NewAtom(fontSize)));
if (0 > gap) gap = -gap; // absolute value
while (0 < gap--) {
aPresContext.ResolvePseudoStyleContextFor(childContent, fontAtom, lastStyleContext,
PR_FALSE, getter_AddRefs(newStyleContext));
if (newStyleContext && newStyleContext.get() != lastStyleContext) {
// create a new frame and append it as sole child of the last created frame
nsIFrame* newFrame = nsnull;
NS_NewMathMLContainerFrame(&newFrame);
NS_ASSERTION(newFrame, "Failed to create new frame");
newFrame->Init(aPresContext, childContent, lastFrame, newStyleContext, nsnull);
if (nsnull == firstFrame) {
firstFrame = newFrame;
}
if (this != lastFrame) {
lastFrame->SetInitialChildList(aPresContext, nsnull, newFrame);
}
lastStyleContext = newStyleContext;
lastFrame = newFrame;
}
else {
break;
}
}
if (nsnull != firstFrame) { // at least one new frame was created
mFrames.ReplaceFrame(this, childFrame, firstFrame);
childFrame->SetParent(lastFrame);
childFrame->SetNextSibling(nsnull);
aPresContext.ReParentStyleContext(childFrame, lastStyleContext);
lastFrame->SetInitialChildList(aPresContext, nsnull, childFrame);
}
}
}
}
}
return rv;
}
/* //////////////////
* Frame construction
* =============================================================================
*/
NS_IMETHODIMP
nsMathMLContainerFrame::Init(nsIPresContext& aPresContext,
nsIContent* aContent,
nsIFrame* aParent,
nsIStyleContext* aContext,
nsIFrame* aPrevInFlow)
{
nsresult rv;
// first, let the base class do its Init()
rv = nsHTMLContainerFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);
// now, if our parent implements the nsIMathMLFrame interface, we inherit
// its scriptlevel and displaystyle. If the parent later wishes to increment
// with other values, it will do so in its SetInitialChildList() method.
mScriptLevel = 0;
mDisplayStyle = PR_TRUE;
nsIMathMLFrame* aMathMLFrame = nsnull;
nsresult res = aParent->QueryInterface(nsIMathMLFrame::GetIID(), (void**)&aMathMLFrame);
if (NS_SUCCEEDED(res) && nsnull != aMathMLFrame) {
PRInt32 aScriptLevel = 0;
PRBool aDisplayStyle = PR_TRUE;
aMathMLFrame->GetPresentationData(&aScriptLevel, &aDisplayStyle);
UpdatePresentationData(aScriptLevel, aDisplayStyle);
}
return rv;
}
NS_IMETHODIMP
nsMathMLContainerFrame::SetInitialChildList(nsIPresContext& aPresContext,
nsIAtom* aListName,
nsIFrame* aChildList)
{
// First, let the base class do its job
nsresult rv;
rv = nsHTMLContainerFrame::SetInitialChildList(aPresContext, aListName, aChildList);
// Next, since we are an inline frame, and since we are a container, we have to
// be very careful with the way we treat our children. Things look okay when
// all of our children are only MathML frames. But there are problems if one of
// our children happens to be an nsInlineFrame, e.g., from generated content such
// as :before { content: open-quote } or :after { content: close-quote }
// The code asserts during reflow (in nsLineLayout::BeginSpan)
// Also there are problems when our children are hybrid, e.g., from html markups.
// In short, the nsInlineFrame class expects a number of *invariants* that are not
// met when we mix things.
// So what we do here is to wrap children that happen to be nsInlineFrames in
// anonymous block frames.
// XXX Question: Do we have to handle Insert/Remove/Append on behalf of
// these anonymous blocks?
// Note: By construction, our anonymous blocks have only one child.
nsIFrame* next = mFrames.FirstChild();
while (next) {
nsIFrame* child = next;
rv = next->GetNextSibling(&next);
if (!IsOnlyWhitespace(child)) {
nsInlineFrame* inlineFrame = nsnull;
rv = child->QueryInterface(nsInlineFrame::kInlineFrameCID, (void**)&inlineFrame);
if (inlineFrame) {
// create a new anonymous block frame to wrap this child...
nsIFrame* anonymous;
rv = NS_NewAnonymousBlockFrame(&anonymous);
if (NS_FAILED(rv))
return rv;
nsCOMPtr<nsIStyleContext> newStyleContext;
aPresContext.ResolvePseudoStyleContextFor(mContent, nsHTMLAtoms::mozAnonymousBlock,
mStyleContext, PR_FALSE,
getter_AddRefs(newStyleContext));
rv = anonymous->Init(aPresContext, mContent, this, newStyleContext, nsnull);
if (NS_FAILED(rv)) {
anonymous->Destroy(aPresContext);
delete anonymous;
return rv;
}
mFrames.ReplaceFrame(this, child, anonymous);
child->SetParent(anonymous);
child->SetNextSibling(nsnull);
aPresContext.ReParentStyleContext(child, newStyleContext);
anonymous->SetInitialChildList(aPresContext, nsnull, child);
}
}
}
return rv;
}
NS_IMETHODIMP
nsMathMLContainerFrame::Reflow(nsIPresContext& aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
nsresult rv = NS_OK;
nsReflowStatus childStatus;
nsHTMLReflowMetrics childDesiredSize(aDesiredSize.maxElementSize);
nsSize availSize(aReflowState.mComputedWidth, aReflowState.mComputedHeight);
nsRect rect;
aStatus = NS_FRAME_NOT_COMPLETE;
aDesiredSize.width = aDesiredSize.height = aDesiredSize.ascent = aDesiredSize.descent = 0;
//////////////////
// Reflow Children
nsIFrame* childFrame = mFrames.FirstChild();
while (nsnull != childFrame) {
//////////////
// WHITESPACE: don't forget that whitespace doesn't count in MathML!
if (IsOnlyWhitespace(childFrame)) {
ReflowEmptyChild(aPresContext, childFrame);
}
else {
nsHTMLReflowState childReflowState(aPresContext, aReflowState, childFrame, availSize);
rv = ReflowChild(childFrame, aPresContext, childDesiredSize, childReflowState, childStatus);
NS_ASSERTION(NS_FRAME_IS_COMPLETE(childStatus), "bad status");
if (NS_FAILED(rv)) {
return rv;
}
// At this stage, the origin points of the children have no use, so we will use the
// origins as placeholders to store the child's ascent and descent. Before return,
// we should set the origins so as to overwrite what we are storing there now.
childFrame->SetRect(&aPresContext,
nsRect(childDesiredSize.descent, childDesiredSize.ascent,
childDesiredSize.width, childDesiredSize.height));
aDesiredSize.width += childDesiredSize.width;
if (aDesiredSize.ascent < childDesiredSize.ascent) {
aDesiredSize.ascent = childDesiredSize.ascent;
}
if (aDesiredSize.descent < childDesiredSize.descent) {
aDesiredSize.descent = childDesiredSize.descent;
}
}
rv = childFrame->GetNextSibling(&childFrame);
NS_ASSERTION(NS_SUCCEEDED(rv),"failed to get next child");
}
aDesiredSize.height = aDesiredSize.ascent + aDesiredSize.descent;
/////////////
// Ask stretchy children to stretch themselves
nsStretchDirection stretchDir = NS_STRETCH_DIRECTION_VERTICAL;
nsCharMetrics parentSize(aDesiredSize);
aDesiredSize.width = aDesiredSize.height = aDesiredSize.ascent = aDesiredSize.descent = 0;
childFrame = mFrames.FirstChild();
while (nsnull != childFrame) {
// retrieve the metrics that was stored at the previous pass
childFrame->GetRect(rect);
nsCharMetrics childSize(rect.x, rect.y, rect.width, rect.height);
//////////
// Stretch ...
// Only directed at frames that implement the nsIMathMLFrame interface
nsIMathMLFrame* aMathMLFrame;
rv = childFrame->QueryInterface(nsIMathMLFrame::GetIID(), (void**)&aMathMLFrame);
if (NS_SUCCEEDED(rv) && nsnull != aMathMLFrame) {
aMathMLFrame->Stretch(aPresContext, stretchDir, parentSize, childSize);
// store the updated metrics
childFrame->SetRect(&aPresContext,
nsRect(childSize.descent, childSize.ascent,
childSize.width, childSize.height));
}
aDesiredSize.width += childSize.width;
if (aDesiredSize.ascent < childSize.ascent) {
aDesiredSize.ascent = childSize.ascent;
}
if (aDesiredSize.descent < childSize.descent) {
aDesiredSize.descent = childSize.descent;
}
rv = childFrame->GetNextSibling(&childFrame);
NS_ASSERTION(NS_SUCCEEDED(rv),"failed to get next child");
}
aDesiredSize.height = aDesiredSize.ascent + aDesiredSize.descent;
/////////////
// Place Children now by re-adjusting the origins to align the baselines
nsPoint offset(0,0);
childFrame = mFrames.FirstChild();
while (nsnull != childFrame) {
childFrame->GetRect(rect);
offset.y = aDesiredSize.ascent - rect.y;
childFrame->MoveTo(&aPresContext, offset.x,offset.y);
offset.x += 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;
}