1 // Copyright 2017 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "third_party/blink/renderer/core/paint/ng/ng_text_painter.h"
6 
7 #include "third_party/blink/renderer/core/css/css_property_names.h"
8 #include "third_party/blink/renderer/core/frame/settings.h"
9 #include "third_party/blink/renderer/core/layout/ng/inline/ng_physical_text_fragment.h"
10 #include "third_party/blink/renderer/core/layout/ng/ng_unpositioned_float.h"
11 #include "third_party/blink/renderer/core/paint/box_painter.h"
12 #include "third_party/blink/renderer/core/paint/paint_info.h"
13 #include "third_party/blink/renderer/core/paint/paint_timing_detector.h"
14 #include "third_party/blink/renderer/core/style/computed_style.h"
15 #include "third_party/blink/renderer/core/style/shadow_list.h"
16 #include "third_party/blink/renderer/platform/fonts/font.h"
17 #include "third_party/blink/renderer/platform/graphics/graphics_context.h"
18 #include "third_party/blink/renderer/platform/graphics/graphics_context_state_saver.h"
19 #include "third_party/blink/renderer/platform/graphics/paint/paint_controller.h"
20 #include "third_party/blink/renderer/platform/wtf/assertions.h"
21 #include "third_party/blink/renderer/platform/wtf/text/character_names.h"
22 
23 namespace blink {
24 
Paint(unsigned start_offset,unsigned end_offset,unsigned length,const TextPaintStyle & text_style,DOMNodeId node_id)25 void NGTextPainter::Paint(unsigned start_offset,
26                           unsigned end_offset,
27                           unsigned length,
28                           const TextPaintStyle& text_style,
29                           DOMNodeId node_id) {
30   GraphicsContextStateSaver state_saver(graphics_context_, false);
31   UpdateGraphicsContext(text_style, state_saver);
32   // TODO(layout-dev): Handle combine text here or elsewhere.
33   PaintInternal<kPaintText>(start_offset, end_offset, length, node_id);
34 
35   if (!emphasis_mark_.IsEmpty()) {
36     if (text_style.emphasis_mark_color != text_style.fill_color)
37       graphics_context_.SetFillColor(text_style.emphasis_mark_color);
38     PaintInternal<kPaintEmphasisMark>(start_offset, end_offset, length,
39                                       node_id);
40   }
41 }
42 
43 // This function paints text twice with different styles in order to:
44 // 1. Paint glyphs inside of |selection_rect| using |selection_style|, and
45 //    outside using |text_style|.
46 // 2. Paint parts of a ligature glyph.
PaintSelectedText(unsigned start_offset,unsigned end_offset,unsigned length,const TextPaintStyle & text_style,const TextPaintStyle & selection_style,const PhysicalRect & selection_rect,DOMNodeId node_id)47 void NGTextPainter::PaintSelectedText(unsigned start_offset,
48                                       unsigned end_offset,
49                                       unsigned length,
50                                       const TextPaintStyle& text_style,
51                                       const TextPaintStyle& selection_style,
52                                       const PhysicalRect& selection_rect,
53                                       DOMNodeId node_id) {
54   if (!fragment_paint_info_.shape_result)
55     return;
56 
57   // Use fast path if all glyphs fit in |selection_rect|. Note |text_bounds_| is
58   // the bounds of all glyphs of this text fragment, including characters before
59   // |start_offset| or after |end_offset|. Computing exact bounds is expensive
60   // that this code only checks bounds of all glyphs.
61   if (selection_rect.Contains(text_bounds_)) {
62     Paint(start_offset, end_offset, length, selection_style, node_id);
63     return;
64   }
65 
66   // Adjust start/end offset when they are in the middle of a ligature. e.g.,
67   // when |start_offset| is between a ligature of "fi", it needs to be adjusted
68   // to before "f".
69   fragment_paint_info_.shape_result->ExpandRangeToIncludePartialGlyphs(
70       &start_offset, &end_offset);
71 
72   // Because only a part of the text glyph can be selected, we need to draw
73   // the selection twice. First, draw the glyphs outside the selection area,
74   // with the original style.
75   FloatRect float_selection_rect(selection_rect);
76   {
77     GraphicsContextStateSaver state_saver(graphics_context_);
78     graphics_context_.ClipOut(float_selection_rect);
79     Paint(start_offset, end_offset, length, text_style, node_id);
80   }
81   // Then draw the glyphs inside the selection area, with the selection style.
82   {
83     GraphicsContextStateSaver state_saver(graphics_context_);
84     graphics_context_.Clip(float_selection_rect);
85     Paint(start_offset, end_offset, length, selection_style, node_id);
86   }
87 }
88 
89 template <NGTextPainter::PaintInternalStep step>
PaintInternalFragment(unsigned from,unsigned to,DOMNodeId node_id)90 void NGTextPainter::PaintInternalFragment(
91     unsigned from,
92     unsigned to,
93     DOMNodeId node_id) {
94   DCHECK(from <= fragment_paint_info_.text.length());
95   DCHECK(to <= fragment_paint_info_.text.length());
96 
97   fragment_paint_info_.from = from;
98   fragment_paint_info_.to = to;
99 
100   if (step == kPaintEmphasisMark) {
101     graphics_context_.DrawEmphasisMarks(
102         font_, fragment_paint_info_, emphasis_mark_,
103         FloatPoint(text_origin_) + IntSize(0, emphasis_mark_offset_));
104   } else {
105     DCHECK(step == kPaintText);
106     graphics_context_.DrawText(font_, fragment_paint_info_,
107                                FloatPoint(text_origin_), node_id);
108     // TODO(npm): Check that there are non-whitespace characters. See
109     // crbug.com/788444.
110     graphics_context_.GetPaintController().SetTextPainted();
111 
112     if (!font_.ShouldSkipDrawing())
113       PaintTimingDetector::NotifyTextPaint(visual_rect_);
114   }
115 }
116 
117 template <NGTextPainter::PaintInternalStep Step>
PaintInternal(unsigned start_offset,unsigned end_offset,unsigned truncation_point,DOMNodeId node_id)118 void NGTextPainter::PaintInternal(unsigned start_offset,
119                                   unsigned end_offset,
120                                   unsigned truncation_point,
121                                   DOMNodeId node_id) {
122   // TODO(layout-dev): We shouldn't be creating text fragments without text.
123   if (!fragment_paint_info_.shape_result)
124     return;
125 
126   if (start_offset <= end_offset) {
127     PaintInternalFragment<Step>(start_offset, end_offset, node_id);
128   } else {
129     if (end_offset > 0) {
130       PaintInternalFragment<Step>(ellipsis_offset_, end_offset, node_id);
131     }
132     if (start_offset < truncation_point) {
133       PaintInternalFragment<Step>(start_offset, truncation_point, node_id);
134     }
135   }
136 }
137 
ClipDecorationsStripe(float upper,float stripe_width,float dilation)138 void NGTextPainter::ClipDecorationsStripe(float upper,
139                                           float stripe_width,
140                                           float dilation) {
141   if (fragment_paint_info_.from >= fragment_paint_info_.to ||
142       !fragment_paint_info_.shape_result)
143     return;
144 
145   Vector<Font::TextIntercept> text_intercepts;
146   font_.GetTextIntercepts(
147       fragment_paint_info_, graphics_context_.DeviceScaleFactor(),
148       graphics_context_.FillFlags(),
149       std::make_tuple(upper, upper + stripe_width), text_intercepts);
150 
151   DecorationsStripeIntercepts(upper, stripe_width, dilation, text_intercepts);
152 }
153 
PaintEmphasisMarkForCombinedText()154 void NGTextPainter::PaintEmphasisMarkForCombinedText() {}
155 
156 }  // namespace blink
157