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- // Copyright (c) 2012 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #ifndef UI_GFX_RENDER_TEXT_H_
- #define UI_GFX_RENDER_TEXT_H_
- #include <stddef.h>
- #include <stdint.h>
- #include <algorithm>
- #include <array>
- #include <cstring>
- #include <memory>
- #include <string>
- #include <utility>
- #include <vector>
- #include "base/i18n/rtl.h"
- #include "base/memory/raw_ptr.h"
- #include "build/build_config.h"
- #include "cc/paint/paint_flags.h"
- #include "third_party/abseil-cpp/absl/types/optional.h"
- #include "third_party/skia/include/core/SkColor.h"
- #include "third_party/skia/include/core/SkFont.h"
- #include "third_party/skia/include/core/SkRefCnt.h"
- #include "ui/gfx/break_list.h"
- #include "ui/gfx/color_palette.h"
- #include "ui/gfx/font_list.h"
- #include "ui/gfx/font_render_params.h"
- #include "ui/gfx/geometry/point.h"
- #include "ui/gfx/geometry/rect.h"
- #include "ui/gfx/geometry/rect_f.h"
- #include "ui/gfx/geometry/size_f.h"
- #include "ui/gfx/geometry/vector2d.h"
- #include "ui/gfx/range/range.h"
- #include "ui/gfx/range/range_f.h"
- #include "ui/gfx/selection_model.h"
- #include "ui/gfx/shadow_value.h"
- #include "ui/gfx/text_constants.h"
- class SkDrawLooper;
- struct SkPoint;
- class SkTypeface;
- namespace cc {
- class PaintCanvas;
- }
- namespace gfx {
- namespace test {
- class RenderTextTestApi;
- }
- class Canvas;
- struct DecoratedText;
- class Font;
- namespace internal {
- class TextRunList;
- // Internal helper class used by derived classes to draw text through Skia.
- class GFX_EXPORT SkiaTextRenderer {
- public:
- explicit SkiaTextRenderer(Canvas* canvas);
- SkiaTextRenderer(const SkiaTextRenderer&) = delete;
- SkiaTextRenderer& operator=(const SkiaTextRenderer&) = delete;
- virtual ~SkiaTextRenderer();
- void SetDrawLooper(sk_sp<SkDrawLooper> draw_looper);
- void SetFontRenderParams(const FontRenderParams& params,
- bool subpixel_rendering_suppressed);
- void SetTypeface(sk_sp<SkTypeface> typeface);
- void SetTextSize(SkScalar size);
- void SetForegroundColor(SkColor foreground);
- void SetShader(sk_sp<cc::PaintShader> shader);
- // TODO(vmpstr): Change this API to mimic SkCanvas::drawTextBlob instead.
- virtual void DrawPosText(const SkPoint* pos,
- const uint16_t* glyphs,
- size_t glyph_count);
- void DrawUnderline(int x, int y, int width, SkScalar thickness_factor = 1.0);
- void DrawStrike(int x, int y, int width, SkScalar thickness_factor);
- private:
- friend class test::RenderTextTestApi;
- raw_ptr<Canvas> canvas_;
- raw_ptr<cc::PaintCanvas> canvas_skia_;
- cc::PaintFlags flags_;
- SkFont font_;
- };
- struct TextToDisplayIndex {
- size_t text_index = 0;
- size_t display_index = 0;
- };
- using TextToDisplaySequence = std::vector<TextToDisplayIndex>;
- using GraphemeIterator = TextToDisplaySequence::const_iterator;
- using StyleArray = std::array<BreakList<bool>, TEXT_STYLE_COUNT>;
- // Internal helper class used to iterate colors, baselines, and styles.
- class StyleIterator {
- public:
- StyleIterator(const BreakList<SkColor>* colors,
- const BreakList<BaselineStyle>* baselines,
- const BreakList<int>* font_size_overrides,
- const BreakList<Font::Weight>* weights,
- const StyleArray* styles);
- StyleIterator(const StyleIterator& style);
- ~StyleIterator();
- StyleIterator& operator=(const StyleIterator& style);
- // Get the colors and styles at the current iterator position.
- SkColor color() const { return color_->second; }
- BaselineStyle baseline() const { return baseline_->second; }
- int font_size_override() const { return font_size_override_->second; }
- bool style(TextStyle s) const { return style_[s]->second; }
- Font::Weight weight() const { return weight_->second; }
- // Get the intersecting range of the current iterator set.
- Range GetRange() const;
- // Get the intersecting range of the current iterator set for attributes that
- // can break text (e.g. not color).
- Range GetTextBreakingRange() const;
- // Update the iterator to point to colors and styles applicable at |position|.
- void IncrementToPosition(size_t position);
- private:
- // Pointers to the breaklists to iterate through. These pointers can't be
- // nullptr and the breaklists must outlive this object.
- raw_ptr<const BreakList<SkColor>> colors_;
- raw_ptr<const BreakList<BaselineStyle>> baselines_;
- raw_ptr<const BreakList<int>> font_size_overrides_;
- raw_ptr<const BreakList<Font::Weight>> weights_;
- raw_ptr<const StyleArray> styles_;
- BreakList<SkColor>::const_iterator color_;
- BreakList<BaselineStyle>::const_iterator baseline_;
- BreakList<int>::const_iterator font_size_override_;
- BreakList<Font::Weight>::const_iterator weight_;
- std::array<BreakList<bool>::const_iterator, TEXT_STYLE_COUNT> style_;
- };
- // Line segments are slices of the display text to be rendered on a single line.
- struct LineSegment {
- LineSegment();
- ~LineSegment();
- // X coordinates of this line segment in text space.
- RangeF x_range;
- // The character range this segment corresponds to.
- Range char_range;
- // Index of the text run that generated this segment.
- size_t run;
- // Returns the width of this line segment in text space.
- float width() const { return x_range.length(); }
- };
- // A line of display text, comprised of a line segment list and some metrics.
- struct Line {
- Line();
- Line(const Line& other);
- ~Line();
- // Segments that make up this line in visual order.
- std::vector<LineSegment> segments;
- // The sum of segment widths and the maximum of segment heights.
- SizeF size;
- // Sum of preceding lines' heights.
- int preceding_heights;
- // Maximum baseline of all segments on this line.
- int baseline;
- // The text index of this line in |text_|.
- int display_text_index = 0;
- };
- // Internal class that contains the results of the text layout and shaping.
- class ShapedText {
- public:
- explicit ShapedText(std::vector<Line> lines);
- ~ShapedText();
- const std::vector<Line>& lines() const { return lines_; }
- private:
- std::vector<Line> lines_;
- };
- // Creates an SkTypeface from a font, |italic| and a desired |weight|.
- // May return null.
- sk_sp<SkTypeface> CreateSkiaTypeface(const Font& font,
- bool italic,
- Font::Weight weight);
- // Applies the given FontRenderParams to the SkFont.
- void ApplyRenderParams(const FontRenderParams& params,
- bool subpixel_rendering_suppressed,
- SkFont* font);
- } // namespace internal
- // RenderText represents an abstract model of styled text and its corresponding
- // visual layout. Support is built in for a cursor, selections, simple styling,
- // complex scripts, and bi-directional text. Implementations provide mechanisms
- // for rendering and translation between logical and visual data.
- class GFX_EXPORT RenderText {
- public:
- #if BUILDFLAG(IS_APPLE)
- // On Mac, while selecting text if the cursor is outside the vertical text
- // bounds, drag to the end of the text.
- static constexpr bool kDragToEndIfOutsideVerticalBounds = true;
- // Mac supports a selection that is "undirected". When undirected, the cursor
- // doesn't know which end of the selection it's at until it first moves.
- static constexpr bool kSelectionIsAlwaysDirected = false;
- #else
- static constexpr bool kDragToEndIfOutsideVerticalBounds = false;
- static constexpr bool kSelectionIsAlwaysDirected = true;
- #endif
- // Invalid value of baseline. Assigning this value to |baseline_| causes
- // re-calculation of baseline.
- static constexpr int kInvalidBaseline = INT_MAX;
- // Default fraction of the text size to use for a strike-through or underline.
- static constexpr SkScalar kLineThicknessFactor = (SK_Scalar1 / 18);
- // The character used for displaying obscured text. Use a bullet character.
- // TODO(pbos): This is highly font dependent, consider replacing the character
- // with a vector glyph.
- static constexpr char16_t kPasswordReplacementChar = 0x2022;
- RenderText(const RenderText&) = delete;
- RenderText& operator=(const RenderText&) = delete;
- virtual ~RenderText();
- // Creates a RenderText instance.
- static std::unique_ptr<RenderText> CreateRenderText();
- // Like above but copies all style settings too.
- std::unique_ptr<RenderText> CreateInstanceOfSameStyle(
- const std::u16string& text) const;
- const std::u16string& text() const { return text_; }
- void SetText(const std::u16string& text);
- void AppendText(const std::u16string& text);
- HorizontalAlignment horizontal_alignment() const {
- return horizontal_alignment_;
- }
- void SetHorizontalAlignment(HorizontalAlignment alignment);
- VerticalAlignment vertical_alignment() const { return vertical_alignment_; }
- void SetVerticalAlignment(VerticalAlignment alignment);
- const FontList& font_list() const { return font_list_; }
- void SetFontList(const FontList& font_list);
- bool cursor_enabled() const { return cursor_enabled_; }
- void SetCursorEnabled(bool cursor_enabled);
- SkColor selection_color() const { return selection_color_; }
- void set_selection_color(SkColor color) { selection_color_ = color; }
- SkColor selection_background_focused_color() const {
- return selection_background_focused_color_;
- }
- void set_selection_background_focused_color(SkColor color) {
- selection_background_focused_color_ = color;
- }
- bool symmetric_selection_visual_bounds() const {
- return symmetric_selection_visual_bounds_;
- }
- void set_symmetric_selection_visual_bounds(bool symmetric) {
- symmetric_selection_visual_bounds_ = symmetric;
- }
- bool focused() const { return focused_; }
- void set_focused(bool focused) { focused_ = focused; }
- bool clip_to_display_rect() const { return clip_to_display_rect_; }
- void set_clip_to_display_rect(bool clip) { clip_to_display_rect_ = clip; }
- // In an obscured (password) field, all text is drawn as bullets.
- bool obscured() const { return obscured_; }
- void SetObscured(bool obscured);
- // Makes a char in obscured text at |index| to be revealed. |index| should be
- // a UTF16 text index. If there is a previous revealed index, the previous one
- // is cleared and only the last set index will be revealed. If |index| is
- // nullopt or out of range, no char will be revealed. The revealed index is
- // also cleared when SetText or SetObscured is called.
- void SetObscuredRevealIndex(absl::optional<size_t> index);
- // For obscured (password) fields, the extra spacing between glyphs.
- int obscured_glyph_spacing() const { return obscured_glyph_spacing_; }
- void SetObscuredGlyphSpacing(int spacing);
- bool multiline() const { return multiline_; }
- void SetMultiline(bool multiline);
- // If multiline, a non-zero value will cap the number of lines rendered,
- // and elide the rest (currently only ELIDE_TAIL supported.)
- void SetMaxLines(size_t max_lines);
- size_t max_lines() const { return max_lines_; }
- // Returns the actual number of lines, broken by |lines_|.
- size_t GetNumLines();
- // Returns the text index of the given line |line|. Returns the text length
- // for any |line| above the number of lines.
- size_t GetTextIndexOfLine(size_t line);
- // TODO(mukai): ELIDE_LONG_WORDS is not supported.
- WordWrapBehavior word_wrap_behavior() const { return word_wrap_behavior_; }
- void SetWordWrapBehavior(WordWrapBehavior behavior);
- // TODO(ckocagil): Add vertical alignment and line spacing support instead.
- int min_line_height() const { return min_line_height_; }
- void SetMinLineHeight(int line_height);
- // Set the maximum length of the layout text, not the actual text.
- // A |length| of 0 forgoes a hard limit, but does not guarantee proper
- // functionality of very long strings. Applies to subsequent SetText calls.
- // WARNING: Only use this for system limits, it lacks complex text support.
- void set_truncate_length(size_t length) { truncate_length_ = length; }
- // The display text will be elided to fit |display_rect| using this behavior.
- void SetElideBehavior(ElideBehavior elide_behavior);
- ElideBehavior elide_behavior() const { return elide_behavior_; }
- // When display text is elided, determines how whitespace is handled.
- // If absl::nullopt is specified, the default elision for the current elide
- // behavior will be applied.
- void SetWhitespaceElision(absl::optional<bool> elide_whitespace);
- absl::optional<bool> whitespace_elision() const {
- return whitespace_elision_;
- }
- const Rect& display_rect() const { return display_rect_; }
- void SetDisplayRect(const Rect& r);
- bool subpixel_rendering_suppressed() const {
- return subpixel_rendering_suppressed_;
- }
- void set_subpixel_rendering_suppressed(bool suppressed) {
- subpixel_rendering_suppressed_ = suppressed;
- }
- const SelectionModel& selection_model() const { return selection_model_; }
- const Range& selection() const { return selection_model_.selection(); }
- size_t cursor_position() const { return selection_model_.caret_pos(); }
- const std::vector<Range>& secondary_selections() const {
- return selection_model_.secondary_selections();
- }
- const std::vector<Range> GetAllSelections() const;
- // Set the cursor to |position|, with the caret affinity trailing the previous
- // grapheme, or if there is no previous grapheme, leading the cursor position.
- // See SelectionModel::caret_affinity_ for details.
- void SetCursorPosition(size_t position);
- // Moves the cursor left or right. Cursor movement is visual, meaning that
- // left and right are relative to screen, not the directionality of the text.
- // |selection_behavior| determines whether a selection is to be made and it's
- // behavior.
- void MoveCursor(BreakType break_type,
- VisualCursorDirection direction,
- SelectionBehavior selection_behavior);
- // Set the selection_model_ to the value of |selection|.
- // The selection range is clamped to text().length() if out of range.
- // Returns true if the cursor position or selection range changed.
- // If any index in |selection_model| is not a cursorable position (not on a
- // grapheme boundary), it is a no-op and returns false.
- bool SetSelection(const SelectionModel& selection);
- // Moves the cursor to the text index corresponding to |point|. If |select| is
- // true, a selection is made with the current selection start index. If the
- // resultant text indices do not lie on valid grapheme boundaries, it is a no-
- // op and returns false. If this move is happening because of a drag causing a
- // selection change, and |drag_origin| is not the zero point, then
- // |drag_origin| overrides the default origin for a select-to-drag
- // (usually the existing text insertion cursor).
- bool MoveCursorToPoint(const gfx::Point& point,
- bool select,
- const gfx::Point& drag_origin = gfx::Point());
- // Set the |selection_model_| based on |range|. If the |range| start or end is
- // greater than text length, it is modified to be the text length. If the
- // |range| start or end is not a cursorable position (not on grapheme
- // boundary), it is a NO-OP and returns false. Otherwise, returns true. If
- // |primary| is true, secondary selections are cleared; otherwise, the range
- // will be added as a secondary selection not associated with the cursor. In
- // the latter case, |range| should not overlap with existing selections.
- bool SelectRange(const Range& range, bool primary = true);
- // Returns true if the local point is over selected text.
- bool IsPointInSelection(const Point& point);
- // Selects no text, keeping the current cursor position and caret affinity.
- void ClearSelection();
- // Select the entire text range. If |reversed| is true, the range will end at
- // the logical beginning of the text; this generally shows the leading portion
- // of text that overflows its display area.
- void SelectAll(bool reversed);
- // Selects the word at the current cursor position. If there is a non-empty
- // selection, the selection bounds are extended to their nearest word
- // boundaries.
- void SelectWord();
- void SetCompositionRange(const Range& composition_range);
- // Set the text color over the entire text or a logical character range.
- // The |range| should be valid, non-reversed, and within [0, text().length()].
- void SetColor(SkColor value);
- void ApplyColor(SkColor value, const Range& range);
- // DEPRECATED.
- // Set the baseline style over the entire text or a logical character range.
- // The |range| should be valid, non-reversed, and within [0, text().length()].
- // TODO(tapted): Remove this. The only client is moving to
- // ApplyFontSizeOverride.
- void SetBaselineStyle(BaselineStyle value);
- void ApplyBaselineStyle(BaselineStyle value, const Range& range);
- // Alters the font size in |range|.
- void ApplyFontSizeOverride(int font_size_override, const Range& range);
- // Set various text styles over the entire text or a logical character range.
- // The respective |style| is applied if |value| is true, or removed if false.
- // The |range| should be valid, non-reversed, and within [0, text().length()].
- void SetStyle(TextStyle style, bool value);
- void ApplyStyle(TextStyle style, bool value, const Range& range);
- void SetWeight(Font::Weight weight);
- void ApplyWeight(Font::Weight weight, const Range& range);
- // Returns whether this style is enabled consistently across the entire
- // RenderText.
- bool GetStyle(TextStyle style) const;
- // Set or get the text directionality mode and get the text direction yielded.
- void SetDirectionalityMode(DirectionalityMode mode);
- DirectionalityMode directionality_mode() const {
- return directionality_mode_;
- }
- base::i18n::TextDirection GetTextDirection() const;
- base::i18n::TextDirection GetDisplayTextDirection();
- // Returns the visual movement direction corresponding to the logical
- // end/beginning of the text, considering only the dominant direction returned
- // by |GetDisplayTextDirection()|, not the direction of a particular run.
- VisualCursorDirection GetVisualDirectionOfLogicalEnd();
- VisualCursorDirection GetVisualDirectionOfLogicalBeginning();
- // Returns the text used to display, which may be obscured, truncated or
- // elided. The subclass may compute elided text on the fly, or use
- // precomputed the elided text.
- virtual const std::u16string& GetDisplayText() = 0;
- // Returns the size required to display the current string (which is the
- // wrapped size in multiline mode). The returned size does not include space
- // reserved for the cursor or the offset text shadows.
- Size GetStringSize();
- // This is same as GetStringSize except that fractional size is returned.
- // The default implementation is same as GetStringSize. Certain platforms that
- // compute the text size as floating-point values, like Mac, will override
- // this method.
- // See comment in Canvas::GetStringWidthF for its usage.
- virtual SizeF GetStringSizeF() = 0;
- // Returns the size of the line containing |caret|.
- virtual SizeF GetLineSizeF(const SelectionModel& caret) = 0;
- // Returns the sum of all the line widths.
- float TotalLineWidth();
- // Returns the width of the content (which is the wrapped width in multiline
- // mode). Reserves room for the cursor if |cursor_enabled_| is true.
- float GetContentWidthF();
- // Same as GetContentWidthF with the width rounded up.
- int GetContentWidth();
- // Returns the common baseline of the text. The return value is the vertical
- // offset from the top of |display_rect_| to the text baseline, in pixels.
- // The baseline is determined from the font list and display rect, and does
- // not depend on the text.
- int GetBaseline();
- // If |select_all| is true, draws as focused with all text selected.
- void Draw(Canvas* canvas, bool select_all = false);
- // Gets the SelectionModel from a visual point in local coordinates. If
- // |drag_origin| is nonzero, it is used as the baseline for
- // out-of-vertical-bounds drags on platforms that have them, instead of the
- // default origin (the insertion cursor's position).
- SelectionModel FindCursorPosition(const Point& point,
- const Point& drag_origin = gfx::Point());
- // Returns true if the position is a valid logical index into text(). Indices
- // amid multi-character graphemes are allowed here, unlike IsValidCursorIndex.
- bool IsValidLogicalIndex(size_t index) const;
- // Returns true if the position is a valid logical index into text(), and is
- // also a valid grapheme boundary, which may be used as a cursor position.
- bool IsValidCursorIndex(size_t index) const;
- // Get the visual bounds of a cursor at |caret|. These bounds typically
- // represent a vertical line if |insert_mode| is true. Pass false for
- // |insert_mode| to retrieve the bounds of the associated glyph. These bounds
- // are in local coordinates, but may be outside the visible region if the text
- // is longer than the textfield. Subsequent text, cursor, or bounds changes
- // may invalidate returned values. Note that |caret| must be placed at
- // grapheme boundary, i.e. caret.caret_pos() must be a cursorable position.
- // TODO(crbug.com/248597): Add multiline support.
- Rect GetCursorBounds(const SelectionModel& caret, bool insert_mode);
- // Compute the current cursor bounds, panning the text to show the cursor in
- // the display rect if necessary. These bounds are in local coordinates.
- // Subsequent text, cursor, or bounds changes may invalidate returned values.
- const Rect& GetUpdatedCursorBounds();
- // Returns a grapheme iterator that contains the codepoint at |index|.
- internal::GraphemeIterator GetGraphemeIteratorAtTextIndex(size_t index) const;
- internal::GraphemeIterator GetGraphemeIteratorAtDisplayTextIndex(
- size_t index) const;
- // For a given grapheme iterator, returns its index.
- size_t GetTextIndex(internal::GraphemeIterator iter) const;
- size_t GetDisplayTextIndex(internal::GraphemeIterator iter) const;
- // Returns true of the current index is at the start of a grapheme.
- bool IsGraphemeBoundary(size_t index) const;
- // Given an |index| in text(), return the next or previous grapheme boundary
- // in logical order (i.e. the nearest cursorable index). The return value is
- // in the range 0 to text().length() inclusive (the input is clamped if it is
- // out of that range). Always moves by at least one character index unless the
- // supplied index is already at the boundary of the string.
- size_t IndexOfAdjacentGrapheme(size_t index,
- LogicalCursorDirection direction) const;
- // Return a SelectionModel with the cursor at the current selection's start.
- // The returned value represents a cursor/caret position without a selection.
- SelectionModel GetSelectionModelForSelectionStart() const;
- // Sets shadows to drawn with text.
- void set_shadows(const ShadowValues& shadows) { shadows_ = shadows; }
- const ShadowValues& shadows() const { return shadows_; }
- // Get the visual bounds containing the logical substring within the |range|.
- // If |range| is empty, the result is empty. This method rounds internally so
- // the returned bounds may be slightly larger than the |range|, but are
- // guaranteed not to be smaller. These bounds could be visually discontinuous
- // if the substring is split by a LTR/RTL level change. These bounds are in
- // local coordinates, but may be outside the visible region if the text is
- // larger than the available space. Subsequent text, cursor, or bounds changes
- // may invalidate returned values.
- virtual std::vector<Rect> GetSubstringBounds(const Range& range) = 0;
- // Gets the horizontal span (relative to the left of the text, not the view)
- // of the sequence of glyphs in |text_range|, over which the cursor will
- // jump when breaking by characters. If the glyphs are RTL then the returned
- // Range will have is_reversed() true. (This does not return a Rect because a
- // Rect can't have a negative width.)
- virtual RangeF GetCursorSpan(const Range& text_range) = 0;
- const Vector2d& GetUpdatedDisplayOffset();
- void SetDisplayOffset(int horizontal_offset);
- void SetDisplayOffset(Vector2d offset);
- // Returns the line offset from the origin after applying the text alignment
- // and the display offset.
- Vector2d GetLineOffset(size_t line_number);
- // Retrieves the word displayed at the given |point| along with its styling
- // information. |point| is in the view's coordinates. If no word is displayed
- // at the point, returns a nearby word. |baseline_point| should correspond to
- // the baseline point of the leftmost glyph of the |word| in the view's
- // coordinates. Returns false, if no word can be retrieved.
- bool GetWordLookupDataAtPoint(const Point& point,
- DecoratedText* decorated_word,
- Point* baseline_point);
- // Retrieves the text at |range| along with its styling information.
- // |baseline_point| should correspond to the baseline point of
- // the leftmost glyph of the text in the view's coordinates. If the text
- // spans multiple lines, |baseline_point| will correspond with the leftmost
- // glyph on the first line in the range. Returns false, if no text can be
- // retrieved.
- bool GetLookupDataForRange(const Range& range,
- DecoratedText* decorated_text,
- Point* baseline_point);
- // Retrieves the text in the given |range|.
- std::u16string GetTextFromRange(const Range& range) const;
- void set_strike_thickness_factor(SkScalar f) { strike_thickness_factor_ = f; }
- // Return the line index that contains the argument; or the index of the last
- // line if the |caret| exceeds the text length.
- virtual size_t GetLineContainingCaret(const SelectionModel& caret) = 0;
- // Expands |range| to its nearest grapheme boundaries and returns the
- // resulting range. Maintains directionality of |range|.
- Range ExpandRangeToGraphemeBoundary(const Range& range) const;
- // Specify the width/height of a glyph for test. The width/height of glyphs is
- // very platform-dependent and environment-dependent. Otherwise multiline text
- // will become really flaky.
- void set_glyph_width_for_test(float width) { glyph_width_for_test_ = width; }
- void set_glyph_height_for_test(float height) {
- glyph_height_for_test_ = height;
- }
- protected:
- RenderText();
- // Whether |segment| corresponds to the newline character. This uses |text_|
- // to look up the corresponding character.
- bool IsNewlineSegment(const internal::LineSegment& segment) const;
- // Whether |segment| corresponds to the newline character inside |text|.
- bool IsNewlineSegment(const std::u16string& text,
- const internal::LineSegment& segment) const;
- // Returns the character range of segments in |line| excluding the trailing
- // newline segment.
- Range GetLineRange(const std::u16string& text,
- const internal::Line& line) const;
- // Returns the text used for layout (e.g. after rewriting, eliding and
- // obscuring characters).
- const std::u16string& GetLayoutText() const;
- // NOTE: The value of these accessors may be stale. Please make sure
- // that these fields are up to date before accessing them.
- const std::u16string& display_text() const { return display_text_; }
- bool text_elided() const { return text_elided_; }
- // Returns an iterator over the |text_| attributes.
- internal::StyleIterator GetTextStyleIterator() const;
- // Returns an iterator over the |layout_text_| attributes.
- internal::StyleIterator GetLayoutTextStyleIterator() const;
- const BreakList<SkColor>& colors() const { return colors_; }
- const BreakList<BaselineStyle>& baselines() const { return baselines_; }
- const BreakList<int>& font_size_overrides() const {
- return font_size_overrides_;
- }
- const BreakList<Font::Weight>& weights() const { return weights_; }
- const internal::StyleArray& styles() const { return styles_; }
- SkScalar strike_thickness_factor() const { return strike_thickness_factor_; }
- const BreakList<SkColor>& layout_colors() const { return layout_colors_; }
- // Whether all the BreakLists have only one break.
- bool IsHomogeneous() const;
- // Returns the shaped text structure. The shaped text contains the visual
- // positions of glyphs required to render the text.
- bool has_shaped_text() const { return shaped_text_ != nullptr; }
- internal::ShapedText* GetShapedText();
- void set_shaped_text(std::unique_ptr<internal::ShapedText> shaped_text) {
- shaped_text_ = std::move(shaped_text);
- }
- // Returns the baseline of the current text. The return value depends on
- // the text and its layout while the return value of GetBaseline() doesn't.
- // GetAlignmentOffset() takes into account the difference between them.
- //
- // We'd like a RenderText to show the text always on the same baseline
- // regardless of the text, so the text does not jump up or down depending
- // on the text. However, underlying layout engines return different baselines
- // depending on the text. In general, layout engines determine the minimum
- // bounding box for the text and return the baseline from the top of the
- // bounding box. So the baseline changes depending on font metrics used to
- // layout the text.
- //
- // For example, suppose there are FontA and FontB and the baseline of FontA
- // is smaller than the one of FontB. If the text is laid out only with FontA,
- // then the baseline of FontA may be returned. If the text includes some
- // characters which are laid out with FontB, then the baseline of FontB may
- // be returned.
- //
- // GetBaseline() returns the fixed baseline regardless of the text.
- // GetDisplayTextBaseline() returns the baseline determined by the underlying
- // layout engine, and it changes depending on the text. GetAlignmentOffset()
- // returns the difference between them.
- int GetDisplayTextBaseline();
- // Get the selection model that visually neighbors |position| by |break_type|.
- // The returned value represents a cursor/caret position without a selection.
- SelectionModel GetAdjacentSelectionModel(const SelectionModel& current,
- BreakType break_type,
- VisualCursorDirection direction);
- // Get the selection model visually left/right of |selection| by one grapheme.
- // The returned value represents a cursor/caret position without a selection.
- virtual SelectionModel AdjacentCharSelectionModel(
- const SelectionModel& selection,
- VisualCursorDirection direction) = 0;
- // Get the selection model visually left/right of |selection| by one word.
- // The returned value represents a cursor/caret position without a selection.
- virtual SelectionModel AdjacentWordSelectionModel(
- const SelectionModel& selection,
- VisualCursorDirection direction) = 0;
- // Get the selection model visually above/below |selection| by one line.
- // The returned value represents a cursor/caret position without a selection.
- virtual SelectionModel AdjacentLineSelectionModel(
- const SelectionModel& selection,
- VisualCursorDirection direction) = 0;
- // Get the selection model corresponding to visual text ends.
- // The returned value represents a cursor/caret position without a selection.
- SelectionModel EdgeSelectionModel(VisualCursorDirection direction);
- // Get the selection model corresponding to visual text ends for |line_index|.
- // The returned value represents a cursor/caret position without a selection.
- SelectionModel LineSelectionModel(size_t line_index,
- gfx::VisualCursorDirection direction);
- // Sets the selection model. |model| should be valid.
- void SetSelectionModel(const SelectionModel& model);
- // Adds a secondary selection. |selection| should not overlap with existing
- // selections.
- void AddSecondarySelection(const Range selection);
- // Convert between indices into |text_| and indices into
- // GetDisplayText(), which differ when the text is obscured,
- // truncated or elided.
- size_t TextIndexToDisplayIndex(size_t index) const;
- size_t DisplayIndexToTextIndex(size_t index) const;
- // Notifies that layout text, or attributes that affect the layout text
- // shape have changed. |text_changed| is true if the content of the
- // |layout_text_| has changed, not just attributes.
- virtual void OnLayoutTextAttributeChanged(bool text_changed);
- // Notifies that attributes that affect the display text shape have changed.
- virtual void OnDisplayTextAttributeChanged() = 0;
- // Ensure the text is laid out, lines are computed, and |lines_| is valid.
- virtual void EnsureLayout() = 0;
- // Draw all text and make the given ranges appear selected.
- virtual void DrawVisualText(internal::SkiaTextRenderer* renderer,
- const std::vector<Range>& selections) = 0;
- // Update the display text.
- void UpdateDisplayText(float text_width);
- // Convert points from the text space to the view space. Handles the display
- // area, display offset, application LTR/RTL mode and multiline. |line| is the
- // index of the line in which |point| is found, and is required to be passed
- // because by the time |point| is in text space, the information to account
- // for certain zero-width characters (such as empty lines) is lost.
- Point ToViewPoint(const PointF& point, size_t line);
- // Get the alignment, resolving ALIGN_TO_HEAD with the current text direction.
- HorizontalAlignment GetCurrentHorizontalAlignment();
- // Returns the line offset from the origin, accounts for text alignment only.
- Vector2d GetAlignmentOffset(size_t line_number);
- // Applies fade effects to |renderer|.
- void ApplyFadeEffects(internal::SkiaTextRenderer* renderer);
- // Applies text shadows to |renderer|.
- void ApplyTextShadows(internal::SkiaTextRenderer* renderer);
- // Get the text direction for the current directionality mode and given
- // |text|.
- base::i18n::TextDirection GetTextDirectionForGivenText(
- const std::u16string& text) const;
- // Adjust ranged styles to accommodate a new |text_| length.
- void UpdateStyleLengths();
- // Adjust ranged styles to accommodate a new |layout_text_| length.
- void UpdateLayoutStyleLengths(size_t max_length) const;
- // Returns the line index for the given argument. |text_y| is relative to
- // the text bounds. Returns -1 if |text_y| is above the text and
- // lines().size() if |text_y| is below it.
- int GetLineContainingYCoord(float text_y);
- // A convenience function to check whether the glyph attached to the caret
- // is within the given range.
- static bool RangeContainsCaret(const Range& range,
- size_t caret_pos,
- LogicalCursorDirection caret_affinity);
- // Returns the baseline, with which the text best appears vertically centered.
- static int DetermineBaselineCenteringText(const int display_height,
- const FontList& font_list);
- // Returns an expanded version of |rect| that is vertically symmetric with
- // respect to the center of |display_rect|.
- static gfx::Rect ExpandToBeVerticallySymmetric(const gfx::Rect& rect,
- const gfx::Rect& display_rect);
- // Given |rects|, sort them along the x-axis and merge intersecting rects
- // using union. Expects all selections in the text to be from the same line.
- static void MergeIntersectingRects(std::vector<Rect>& rects);
- // Resets |cached_cursor_x_| to null. When non-null, CURSOR_UP, CURSOR_DOWN
- // movements use this value instead of the current cursor x position to
- // determine the next cursor x position.
- void reset_cached_cursor_x() { cached_cursor_x_.reset(); }
- void set_cached_cursor_x(int x) { cached_cursor_x_ = x; }
- absl::optional<int> cached_cursor_x() const { return cached_cursor_x_; }
- // Fixed width of glyphs. This should only be set in test environments.
- float glyph_width_for_test_ = 0;
- // Fixed height of glyphs. This should only be set in test environments.
- float glyph_height_for_test_ = 0;
- private:
- friend class test::RenderTextTestApi;
- // Resets |layout_text_| and |display_text_| and marks them dirty.
- void OnTextAttributeChanged();
- // Computes the |layout_text_| by rewriting it from |text_|, if needed.
- // Computes the layout break lists, if needed.
- void EnsureLayoutTextUpdated() const;
- // Elides |text| as needed to fit in the |available_width| using |behavior|.
- // |text_width| is the pre-calculated width of the text shaped by this render
- // text, or pass 0 if the width is unknown.
- std::u16string Elide(const std::u16string& text,
- float text_width,
- float available_width,
- ElideBehavior behavior);
- // Elides |email| as needed to fit the |available_width|.
- std::u16string ElideEmail(const std::u16string& email, float available_width);
- // Update the cached bounds and display offset to ensure that the current
- // cursor is within the visible display area.
- void UpdateCachedBoundsAndOffset();
- // Draws the specified ranges of text with a selected appearance.
- void DrawSelections(Canvas* canvas, const std::vector<Range>& selections);
- // Returns a grapheme iterator that contains the codepoint at |index|.
- internal::GraphemeIterator GetGraphemeIteratorAtIndex(
- const std::u16string& text,
- const size_t internal::TextToDisplayIndex::*field,
- size_t index) const;
- // Returns the nearest word start boundary for |index|. First searches in the
- // CURSOR_BACKWARD direction, then in the CURSOR_FORWARD direction. Returns
- // the text length if no valid boundary is found.
- size_t GetNearestWordStartBoundary(size_t index) const;
- // Expands |range| to its nearest word boundaries and returns the resulting
- // range. Maintains directionality of |range|.
- Range ExpandRangeToWordBoundary(const Range& range) const;
- // Returns an implementation-specific run list, if implemented.
- virtual internal::TextRunList* GetRunList() = 0;
- virtual const internal::TextRunList* GetRunList() const = 0;
- // Returns the decorated text corresponding to |range|. Returns false if the
- // text cannot be retrieved, e.g. if the text is obscured.
- virtual bool GetDecoratedTextForRange(const Range& range,
- DecoratedText* decorated_text) = 0;
- // Logical UTF-16 string data to be drawn.
- std::u16string text_;
- // Horizontal alignment of the text with respect to |display_rect_|. The
- // default is to align left if the application UI is LTR and right if RTL.
- HorizontalAlignment horizontal_alignment_{base::i18n::IsRTL() ? ALIGN_RIGHT
- : ALIGN_LEFT};
- // Vertical alignment of the text with respect to |display_rect_|. Only
- // applicable when |multiline_| is true. The default is to align center.
- VerticalAlignment vertical_alignment_ = ALIGN_MIDDLE;
- // The text directionality mode, defaults to DIRECTIONALITY_FROM_TEXT.
- DirectionalityMode directionality_mode_ = DIRECTIONALITY_FROM_TEXT;
- // The cached text direction, potentially computed from the text or UI locale.
- // Use GetTextDirection(), do not use this potentially invalid value directly!
- mutable base::i18n::TextDirection text_direction_ =
- base::i18n::UNKNOWN_DIRECTION;
- mutable base::i18n::TextDirection display_text_direction_ =
- base::i18n::UNKNOWN_DIRECTION;
- // A list of fonts used to render |text_|.
- FontList font_list_;
- // Logical selection ranges and visual cursor position.
- SelectionModel selection_model_;
- // The cached cursor bounds; get these bounds with GetUpdatedCursorBounds.
- Rect cursor_bounds_;
- // Specifies whether the cursor is enabled. If disabled, no space is reserved
- // for the cursor when positioning text.
- bool cursor_enabled_ = true;
- // Whether the current selection has a known direction. That is, whether a
- // directional input (e.g. arrow key) has been received for the current
- // selection to indicate which end of the selection has the caret. When true,
- // directed inputs preserve (rather than replace) the selection affinity.
- bool has_directed_selection_ = kSelectionIsAlwaysDirected;
- // The color used for drawing selected text.
- SkColor selection_color_ = kPlaceholderColor;
- // The background color used for drawing the selection when focused.
- SkColor selection_background_focused_color_ = kPlaceholderColor;
- // Whether the selection visual bounds should be expanded vertically to be
- // vertically symmetric with respect to the display rect. Note this flag has
- // no effect on multi-line text.
- bool symmetric_selection_visual_bounds_ = false;
- // The focus state of the text.
- bool focused_ = false;
- // Composition text range.
- Range composition_range_ = Range::InvalidRange();
- // Color, baseline, and style breaks, used to modify ranges of text.
- // BreakList positions are stored with text indices, not display indices.
- // TODO(msw): Expand to support cursor, selection, background, etc. colors.
- BreakList<SkColor> colors_{kPlaceholderColor};
- BreakList<BaselineStyle> baselines_{NORMAL_BASELINE};
- BreakList<int> font_size_overrides_{0};
- BreakList<Font::Weight> weights_{Font::Weight::NORMAL};
- internal::StyleArray styles_;
- mutable BreakList<SkColor> layout_colors_;
- mutable BreakList<BaselineStyle> layout_baselines_;
- mutable BreakList<int> layout_font_size_overrides_;
- mutable BreakList<Font::Weight> layout_weights_;
- mutable internal::StyleArray layout_styles_;
- // A mapping from text to display text indices for each grapheme. The vector
- // contains an ordered sequence of indice pairs. Both sequence |text_index|
- // and |display_index| are sorted.
- mutable internal::TextToDisplaySequence text_to_display_indices_;
- // A flag to obscure actual text with asterisks for password fields.
- bool obscured_ = false;
- // The index at which the char should be revealed in the obscured text.
- absl::optional<size_t> obscured_reveal_index_;
- // The maximum length of text to display, 0 forgoes a hard limit.
- size_t truncate_length_ = 0;
- // The obscured and/or truncated text used to layout the text to display.
- mutable std::u16string layout_text_;
- // The elided text displayed visually. This is empty if the text
- // does not have to be elided, or became empty as a result of eliding.
- // TODO(oshima): When the text is elided, painting can be done only with
- // display text info, so it should be able to clear the |layout_text_| and
- // associated information.
- mutable std::u16string display_text_;
- // The behavior for eliding, fading, or truncating.
- ElideBehavior elide_behavior_ = NO_ELIDE;
- // The behavior for eliding whitespace when eliding or truncating.
- absl::optional<bool> whitespace_elision_;
- // True if the text is elided given the current behavior and display area.
- bool text_elided_ = false;
- // The minimum height a line should have.
- int min_line_height_ = 0;
- // Whether the text should be broken into multiple lines. Uses the width of
- // |display_rect_| as the width cap.
- bool multiline_ = false;
- // If multiple lines, the maximum number of lines to render, or 0.
- size_t max_lines_ = 0;
- // The wrap behavior when the text is broken into lines. Do nothing unless
- // |multiline_| is set. The default value is IGNORE_LONG_WORDS.
- WordWrapBehavior word_wrap_behavior_ = IGNORE_LONG_WORDS;
- // Set to true to suppress subpixel rendering due to non-font reasons (eg.
- // if the background is transparent). The default value is false.
- bool subpixel_rendering_suppressed_ = false;
- // The local display area for rendering the text.
- Rect display_rect_;
- // Flag to work around a Skia bug with the PDF path (http://crbug.com/133548)
- // that results in incorrect clipping when drawing to the document margins.
- // This field allows disabling clipping to work around the issue.
- // TODO(asvitkine): Remove this when the underlying Skia bug is fixed.
- bool clip_to_display_rect_ = true;
- // The offset for the text to be drawn, relative to the display area.
- // Get this point with GetUpdatedDisplayOffset (or risk using a stale value).
- Vector2d display_offset_;
- // The baseline of the text. This is determined from the height of the
- // display area and the cap height of the font list so the text is vertically
- // centered.
- int baseline_ = kInvalidBaseline;
- // The cached bounds and offset are invalidated by changes to the cursor,
- // selection, font, and other operations that adjust the visible text bounds.
- bool cached_bounds_and_offset_valid_ = false;
- // Text shadows to be drawn.
- ShadowValues shadows_;
- // Text shaping computed by EnsureLayout. This should be invalidated upon
- // OnLayoutTextAttributeChanged and OnDisplayTextAttributeChanged calls.
- std::unique_ptr<internal::ShapedText> shaped_text_;
- // The ratio of strike-through line thickness to text height.
- SkScalar strike_thickness_factor_ = kLineThicknessFactor;
- // Extra spacing placed between glyphs; used only for obscured text styling.
- int obscured_glyph_spacing_ = 0;
- // The cursor position in view space, used to traverse lines of varied widths.
- absl::optional<int> cached_cursor_x_;
- // Tell whether or not the |layout_text_| needs an update or is up to date.
- mutable bool layout_text_up_to_date_ = false;
- };
- } // namespace gfx
- #endif // UI_GFX_RENDER_TEXT_H_
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