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-rw-r--r--layout/style/nsFontFaceUtils.cpp231
1 files changed, 231 insertions, 0 deletions
diff --git a/layout/style/nsFontFaceUtils.cpp b/layout/style/nsFontFaceUtils.cpp
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+++ b/layout/style/nsFontFaceUtils.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsFontFaceUtils.h"
+
+#include "gfxTextRun.h"
+#include "gfxUserFontSet.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/RestyleManager.h"
+#include "nsFontMetrics.h"
+#include "nsIFrame.h"
+#include "nsLayoutUtils.h"
+#include "nsPlaceholderFrame.h"
+#include "nsTArray.h"
+
+using namespace mozilla;
+
+enum class FontUsageKind {
+ // The frame did not use the given font.
+ None = 0,
+ // The frame uses the given font, but doesn't use font-metric-dependent units,
+ // which means that its style doesn't depend on this font.
+ Frame = 1 << 0,
+ // The frame uses has some font-metric-dependent units on this font.
+ // This means that its style depends on this font, and we need to restyle the
+ // element the frame came from.
+ FontMetrics = 1 << 1,
+
+ Max = Frame | FontMetrics,
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(FontUsageKind);
+
+static bool IsFontReferenced(const ComputedStyle& aStyle,
+ const nsAString& aFamilyName) {
+ for (const auto& family :
+ aStyle.StyleFont()->mFont.family.families.list.AsSpan()) {
+ if (family.IsNamedFamily(aFamilyName)) {
+ return true;
+ }
+ }
+ return false;
+}
+
+static FontUsageKind StyleFontUsage(nsIFrame* aFrame, ComputedStyle* aStyle,
+ nsPresContext* aPresContext,
+ const gfxUserFontEntry* aFont,
+ const nsAString& aFamilyName,
+ bool aIsExtraStyle) {
+ MOZ_ASSERT(NS_ConvertUTF8toUTF16(aFont->FamilyName()) == aFamilyName);
+
+ auto FontIsUsed = [&aFont, &aPresContext,
+ &aFamilyName](ComputedStyle* aStyle) {
+ if (!IsFontReferenced(*aStyle, aFamilyName)) {
+ return false;
+ }
+
+ // family name is in the fontlist, check to see if the font group
+ // associated with the frame includes the specific userfont.
+ //
+ // TODO(emilio): Is this check really useful? I guess it's useful for
+ // different font faces of the same font?
+ RefPtr<nsFontMetrics> fm = nsLayoutUtils::GetFontMetricsForComputedStyle(
+ aStyle, aPresContext, 1.0f);
+ return fm->GetThebesFontGroup()->ContainsUserFont(aFont);
+ };
+
+ auto usage = FontUsageKind::None;
+
+ if (FontIsUsed(aStyle)) {
+ usage |= FontUsageKind::Frame;
+ if (aStyle->DependsOnSelfFontMetrics()) {
+ usage |= FontUsageKind::FontMetrics;
+ }
+ }
+
+ if (aStyle->DependsOnInheritedFontMetrics() &&
+ !(usage & FontUsageKind::FontMetrics)) {
+ ComputedStyle* parentStyle = nullptr;
+ if (aIsExtraStyle) {
+ parentStyle = aFrame->Style();
+ } else {
+ nsIFrame* provider = nullptr;
+ parentStyle = aFrame->GetParentComputedStyle(&provider);
+ }
+
+ if (parentStyle && FontIsUsed(parentStyle)) {
+ usage |= FontUsageKind::FontMetrics;
+ }
+ }
+
+ return usage;
+}
+
+static FontUsageKind FrameFontUsage(nsIFrame* aFrame,
+ nsPresContext* aPresContext,
+ const gfxUserFontEntry* aFont,
+ const nsAString& aFamilyName) {
+ // check the style of the frame
+ FontUsageKind kind = StyleFontUsage(aFrame, aFrame->Style(), aPresContext,
+ aFont, aFamilyName, /* extra = */ false);
+ if (kind == FontUsageKind::Max) {
+ return kind;
+ }
+
+ // check additional styles
+ int32_t contextIndex = 0;
+ for (ComputedStyle* extraContext;
+ (extraContext = aFrame->GetAdditionalComputedStyle(contextIndex));
+ ++contextIndex) {
+ kind |= StyleFontUsage(aFrame, extraContext, aPresContext, aFont,
+ aFamilyName, /* extra = */ true);
+ if (kind == FontUsageKind::Max) {
+ break;
+ }
+ }
+
+ return kind;
+}
+
+// TODO(emilio): Can we use the restyle-hint machinery instead of this?
+static void ScheduleReflow(PresShell* aPresShell, nsIFrame* aFrame) {
+ nsIFrame* f = aFrame;
+ if (f->IsFrameOfType(nsIFrame::eSVG) || f->IsInSVGTextSubtree()) {
+ // SVG frames (and the non-SVG descendants of an SVGTextFrame) need special
+ // reflow handling. We need to search upwards for the first displayed
+ // SVGOuterSVGFrame or non-SVG frame, which is the frame we can call
+ // FrameNeedsReflow on. (This logic is based on
+ // SVGUtils::ScheduleReflowSVG and
+ // SVGTextFrame::ScheduleReflowSVGNonDisplayText.)
+ if (f->HasAnyStateBits(NS_FRAME_IS_NONDISPLAY)) {
+ while (f) {
+ if (!f->HasAnyStateBits(NS_FRAME_IS_NONDISPLAY)) {
+ if (f->IsSubtreeDirty()) {
+ // This is a displayed frame, so if it is already dirty, we
+ // will be reflowed soon anyway. No need to call
+ // FrameNeedsReflow again, then.
+ return;
+ }
+ if (!f->HasAnyStateBits(NS_FRAME_SVG_LAYOUT) ||
+ !f->IsInSVGTextSubtree()) {
+ break;
+ }
+ f->AddStateBits(NS_FRAME_HAS_DIRTY_CHILDREN);
+ }
+ f = f->GetParent();
+ }
+ MOZ_ASSERT(f, "should have found an ancestor frame to reflow");
+ }
+ }
+
+ aPresShell->FrameNeedsReflow(f, IntrinsicDirty::FrameAncestorsAndDescendants,
+ NS_FRAME_IS_DIRTY);
+}
+
+enum class ReflowAlreadyScheduled {
+ No,
+ Yes,
+};
+
+/* static */
+void nsFontFaceUtils::MarkDirtyForFontChange(nsIFrame* aSubtreeRoot,
+ const gfxUserFontEntry* aFont) {
+ MOZ_ASSERT(aFont);
+ AutoTArray<nsIFrame*, 4> subtrees;
+ subtrees.AppendElement(aSubtreeRoot);
+
+ nsPresContext* pc = aSubtreeRoot->PresContext();
+ PresShell* presShell = pc->PresShell();
+
+ const bool usesMetricsFromStyle = pc->StyleSet()->UsesFontMetrics();
+
+ // StyleSingleFontFamily::IsNamedFamily expects a UTF-16 string. Convert it
+ // once here rather than on each call.
+ NS_ConvertUTF8toUTF16 familyName(aFont->FamilyName());
+
+ // check descendants, iterating over subtrees that may include
+ // additional subtrees associated with placeholders
+ do {
+ nsIFrame* subtreeRoot = subtrees.PopLastElement();
+
+ // Check all descendants to see if they use the font
+ AutoTArray<std::pair<nsIFrame*, ReflowAlreadyScheduled>, 32> stack;
+ stack.AppendElement(
+ std::make_pair(subtreeRoot, ReflowAlreadyScheduled::No));
+
+ do {
+ auto pair = stack.PopLastElement();
+ nsIFrame* f = pair.first;
+ ReflowAlreadyScheduled alreadyScheduled = pair.second;
+
+ // if this frame uses the font, mark its descendants dirty
+ // and skip checking its children
+ FontUsageKind kind = FrameFontUsage(f, pc, aFont, familyName);
+ if (kind != FontUsageKind::None) {
+ if ((kind & FontUsageKind::Frame) &&
+ alreadyScheduled == ReflowAlreadyScheduled::No) {
+ ScheduleReflow(presShell, f);
+ alreadyScheduled = ReflowAlreadyScheduled::Yes;
+ }
+ if (kind & FontUsageKind::FontMetrics) {
+ MOZ_ASSERT(f->GetContent() && f->GetContent()->IsElement(),
+ "How could we target a non-element with selectors?");
+ f->PresContext()->RestyleManager()->PostRestyleEvent(
+ dom::Element::FromNode(f->GetContent()),
+ RestyleHint::RECASCADE_SELF, nsChangeHint(0));
+ }
+ }
+
+ if (alreadyScheduled == ReflowAlreadyScheduled::No ||
+ usesMetricsFromStyle) {
+ if (f->IsPlaceholderFrame()) {
+ nsIFrame* oof = nsPlaceholderFrame::GetRealFrameForPlaceholder(f);
+ if (!nsLayoutUtils::IsProperAncestorFrame(subtreeRoot, oof)) {
+ // We have another distinct subtree we need to mark.
+ subtrees.AppendElement(oof);
+ }
+ }
+
+ for (const auto& childList : f->ChildLists()) {
+ for (nsIFrame* kid : childList.mList) {
+ stack.AppendElement(std::make_pair(kid, alreadyScheduled));
+ }
+ }
+ }
+ } while (!stack.IsEmpty());
+ } while (!subtrees.IsEmpty());
+}