pjs/layout/generic/nsFontInflationData.cpp

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/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* ***** 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 the font size inflation manager.
*
* The Initial Developer of the Original Code is the Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2012
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* L. David Baron <dbaron@dbaron.org>, Mozilla Corporation (original author)
*
* Alternatively, the contents of this file may be used under the terms of
* either 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 ***** */
/* Per-block-formatting-context manager of font size inflation for pan and zoom UI. */
#include "nsFontInflationData.h"
#include "FramePropertyTable.h"
#include "nsTextFragment.h"
#include "nsIFormControlFrame.h"
#include "nsHTMLReflowState.h"
#include "nsTextFrameUtils.h"
using namespace mozilla;
using namespace mozilla::layout;
static void
DestroyFontInflationData(void *aPropertyValue)
{
delete static_cast<nsFontInflationData*>(aPropertyValue);
}
NS_DECLARE_FRAME_PROPERTY(FontInflationDataProperty, DestroyFontInflationData);
/* static */ nsFontInflationData*
nsFontInflationData::FindFontInflationDataFor(const nsIFrame *aFrame)
{
// We have one set of font inflation data per block formatting context.
const nsIFrame *bfc = FlowRootFor(aFrame);
NS_ASSERTION(bfc->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
"should have found a flow root");
return static_cast<nsFontInflationData*>(
bfc->Properties().Get(FontInflationDataProperty()));
}
/* static */ void
nsFontInflationData::UpdateFontInflationDataWidthFor(const nsHTMLReflowState& aReflowState)
{
nsIFrame *bfc = aReflowState.frame;
NS_ASSERTION(bfc->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
"should have been given a flow root");
FrameProperties bfcProps(bfc->Properties());
nsFontInflationData *data = static_cast<nsFontInflationData*>(
bfcProps.Get(FontInflationDataProperty()));
if (!data) {
data = new nsFontInflationData(bfc);
bfcProps.Set(FontInflationDataProperty(), data);
}
data->UpdateWidth(aReflowState);
}
/* static */ void
nsFontInflationData::MarkFontInflationDataTextDirty(nsIFrame *aBFCFrame)
{
NS_ASSERTION(aBFCFrame->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
"should have been given a flow root");
FrameProperties bfcProps(aBFCFrame->Properties());
nsFontInflationData *data = static_cast<nsFontInflationData*>(
bfcProps.Get(FontInflationDataProperty()));
if (data) {
data->MarkTextDirty();
}
}
nsFontInflationData::nsFontInflationData(nsIFrame *aBFCFrame)
: mBFCFrame(aBFCFrame)
, mTextAmount(0)
, mTextThreshold(0)
, mInflationEnabled(false)
, mTextDirty(true)
{
}
/**
* Find the closest common ancestor between aFrame1 and aFrame2, except
* treating the parent of a frame as the first-in-flow of its parent (so
* the result doesn't change when breaking changes).
*
* aKnownCommonAncestor is a known common ancestor of both.
*/
static nsIFrame*
NearestCommonAncestorFirstInFlow(nsIFrame *aFrame1, nsIFrame *aFrame2,
nsIFrame *aKnownCommonAncestor)
{
aFrame1 = aFrame1->GetFirstInFlow();
aFrame2 = aFrame2->GetFirstInFlow();
aKnownCommonAncestor = aKnownCommonAncestor->GetFirstInFlow();
nsAutoTArray<nsIFrame*, 32> ancestors1, ancestors2;
for (nsIFrame *f = aFrame1; f != aKnownCommonAncestor;
(f = f->GetParent()) && (f = f->GetFirstInFlow())) {
ancestors1.AppendElement(f);
}
for (nsIFrame *f = aFrame2; f != aKnownCommonAncestor;
(f = f->GetParent()) && (f = f->GetFirstInFlow())) {
ancestors2.AppendElement(f);
}
nsIFrame *result = aKnownCommonAncestor;
PRUint32 i1 = ancestors1.Length(),
i2 = ancestors2.Length();
while (i1-- != 0 && i2-- != 0) {
if (ancestors1[i1] != ancestors2[i2]) {
break;
}
result = ancestors1[i1];
}
return result;
}
static nscoord
ComputeDescendantWidth(const nsHTMLReflowState& aAncestorReflowState,
nsIFrame *aDescendantFrame)
{
nsIFrame *ancestorFrame = aAncestorReflowState.frame->GetFirstInFlow();
if (aDescendantFrame == ancestorFrame) {
return aAncestorReflowState.ComputedWidth();
}
AutoInfallibleTArray<nsIFrame*, 16> frames;
for (nsIFrame *f = aDescendantFrame; f != ancestorFrame;
f = f->GetParent()) {
frames.AppendElement(f);
}
PRUint32 len = frames.Length();
nsHTMLReflowState *reflowStates = static_cast<nsHTMLReflowState*>
(moz_xmalloc(sizeof(nsHTMLReflowState) * len));
nsPresContext *presContext = aDescendantFrame->PresContext();
for (PRUint32 i = 0; i < len; ++i) {
const nsHTMLReflowState &parentReflowState =
(i == 0) ? aAncestorReflowState : reflowStates[i - 1];
nsSize availSize(parentReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
nsIFrame *frame = frames[len - i - 1];
NS_ABORT_IF_FALSE(frame->GetParent()->GetFirstInFlow() ==
parentReflowState.frame->GetFirstInFlow(),
"bad logic in this function");
new (reflowStates + i) nsHTMLReflowState(presContext, parentReflowState,
frame, availSize);
}
NS_ABORT_IF_FALSE(reflowStates[len - 1].frame == aDescendantFrame,
"bad logic in this function");
nscoord result = reflowStates[len - 1].ComputedWidth();
for (PRUint32 i = len; i-- != 0; ) {
reflowStates[i].~nsHTMLReflowState();
}
moz_free(reflowStates);
return result;
}
void
nsFontInflationData::UpdateWidth(const nsHTMLReflowState &aReflowState)
{
nsIFrame *bfc = aReflowState.frame;
NS_ASSERTION(bfc->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
"must be block formatting context");
nsIFrame *firstInflatableDescendant =
FindEdgeInflatableFrameIn(bfc, eFromStart);
if (!firstInflatableDescendant) {
mTextAmount = 0;
mTextThreshold = 0; // doesn't matter
mTextDirty = false;
mInflationEnabled = false;
return;
}
nsIFrame *lastInflatableDescendant =
FindEdgeInflatableFrameIn(bfc, eFromEnd);
NS_ABORT_IF_FALSE(!firstInflatableDescendant == !lastInflatableDescendant,
"null-ness should match; NearestCommonAncestorFirstInFlow"
" will crash when passed null");
// Particularly when we're computing for the root BFC, the width of
// nca might differ significantly for the width of bfc.
nsIFrame *nca = NearestCommonAncestorFirstInFlow(firstInflatableDescendant,
lastInflatableDescendant,
bfc);
while (!nsLayoutUtils::IsContainerForFontSizeInflation(nca)) {
nca = nca->GetParent();
}
nscoord newNCAWidth = ComputeDescendantWidth(aReflowState, nca);
// See comment above "font.size.inflation.lineThreshold" in
// modules/libpref/src/init/all.js .
PRUint32 lineThreshold = nsLayoutUtils::FontSizeInflationLineThreshold();
nscoord newTextThreshold = (newNCAWidth * lineThreshold) / 100;
if (mTextThreshold <= mTextAmount && mTextAmount < newTextThreshold) {
// Because we truncate our scan when we hit sufficient text, we now
// need to rescan.
mTextDirty = true;
}
mTextThreshold = newTextThreshold;
mInflationEnabled = mTextAmount >= mTextThreshold;
}
/* static */ nsIFrame*
nsFontInflationData::FindEdgeInflatableFrameIn(nsIFrame* aFrame,
SearchDirection aDirection)
{
// NOTE: This function has a similar structure to ScanTextIn!
// FIXME: Should probably only scan the text that's actually going to
// be inflated!
nsIFormControlFrame* fcf = do_QueryFrame(aFrame);
if (fcf) {
return aFrame;
}
// FIXME: aDirection!
nsAutoTArray<FrameChildList, 4> lists;
aFrame->GetChildLists(&lists);
for (PRUint32 i = 0, len = lists.Length(); i < len; ++i) {
const nsFrameList& list =
lists[(aDirection == eFromStart) ? i : len - i - 1].mList;
for (nsIFrame *kid = (aDirection == eFromStart) ? list.FirstChild()
: list.LastChild();
kid;
kid = (aDirection == eFromStart) ? kid->GetNextSibling()
: kid->GetPrevSibling()) {
if (kid->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT) {
// Goes in a different set of inflation data.
continue;
}
if (kid->GetType() == nsGkAtoms::textFrame) {
nsIContent *content = kid->GetContent();
if (content && kid == content->GetPrimaryFrame()) {
PRUint32 len = nsTextFrameUtils::
ComputeApproximateLengthWithWhitespaceCompression(
content, kid->GetStyleText());
if (len != 0) {
return kid;
}
}
} else {
nsIFrame *kidResult =
FindEdgeInflatableFrameIn(kid, aDirection);
if (kidResult) {
return kidResult;
}
}
}
}
return nsnull;
}
void
nsFontInflationData::ScanText()
{
mTextDirty = false;
mTextAmount = 0;
ScanTextIn(mBFCFrame);
mInflationEnabled = mTextAmount >= mTextThreshold;
}
void
nsFontInflationData::ScanTextIn(nsIFrame *aFrame)
{
// NOTE: This function has a similar structure to FindEdgeInflatableFrameIn!
// FIXME: Should probably only scan the text that's actually going to
// be inflated!
nsIFrame::ChildListIterator lists(aFrame);
for (; !lists.IsDone(); lists.Next()) {
nsFrameList::Enumerator kids(lists.CurrentList());
for (; !kids.AtEnd(); kids.Next()) {
nsIFrame *kid = kids.get();
if (kid->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT) {
// Goes in a different set of inflation data.
continue;
}
if (kid->GetType() == nsGkAtoms::textFrame) {
nsIContent *content = kid->GetContent();
if (content && kid == content->GetPrimaryFrame()) {
PRUint32 len = nsTextFrameUtils::
ComputeApproximateLengthWithWhitespaceCompression(
content, kid->GetStyleText());
if (len != 0) {
nscoord fontSize = kid->GetStyleFont()->mFont.size;
if (fontSize > 0) {
mTextAmount += fontSize * len;
}
}
}
} else {
// recursive step
ScanTextIn(kid);
}
if (mTextAmount >= mTextThreshold) {
return;
}
}
}
}