summaryrefslogtreecommitdiffstats
path: root/layout/style/nsFontFaceUtils.cpp
blob: fdf50954369419d2ddd7845b9643154a1bd7f948 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
/* -*- 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->IsSVGFrame() || 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());
}