// 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_ #pragma once #include #include #include #include "base/gtest_prod_util.h" #include "base/i18n/rtl.h" #include "base/string16.h" #include "third_party/skia/include/core/SkColor.h" #include "third_party/skia/include/core/SkPaint.h" #include "ui/base/range/range.h" #include "ui/gfx/font_list.h" #include "ui/gfx/point.h" #include "ui/gfx/rect.h" #include "ui/gfx/selection_model.h" class SkCanvas; struct SkPoint; namespace gfx { class Canvas; class RenderTextTest; class ShadowValue; struct StyleRange; namespace internal { // Internal helper class used by derived classes to draw text through Skia. class SkiaTextRenderer { public: explicit SkiaTextRenderer(Canvas* canvas); ~SkiaTextRenderer(); void SetDrawLooper(SkDrawLooper* draw_looper); void SetFontSmoothingSettings(bool enable_smoothing, bool enable_lcd_text); void SetTypeface(SkTypeface* typeface); void SetTextSize(int size); void SetFontFamilyWithStyle(const std::string& family, int font_style); void SetForegroundColor(SkColor foreground); void SetShader(SkShader* shader); void DrawSelection(const std::vector& selection, SkColor color); void DrawPosText(const SkPoint* pos, const uint16* glyphs, size_t glyph_count); void DrawDecorations(int x, int y, int width, const StyleRange& style); private: SkCanvas* canvas_skia_; SkPaint paint_; DISALLOW_COPY_AND_ASSIGN(SkiaTextRenderer); }; } // namespace internal // A visual style applicable to a range of text. struct UI_EXPORT StyleRange { StyleRange(); SkColor foreground; // A gfx::Font::FontStyle flag to specify bold and italic styles. int font_style; bool strike; bool diagonal_strike; bool underline; ui::Range range; }; typedef std::vector StyleRanges; // TODO(msw): Distinguish between logical character stops and glyph stops? // CHARACTER_BREAK cursor movements should stop at neighboring characters. // WORD_BREAK cursor movements should stop at the nearest word boundaries. // LINE_BREAK cursor movements should stop at the text ends as shown on screen. enum BreakType { CHARACTER_BREAK, WORD_BREAK, LINE_BREAK, }; // Horizontal text alignment styles. enum HorizontalAlignment { ALIGN_LEFT, ALIGN_CENTER, ALIGN_RIGHT, }; // RenderText represents an abstract model of styled text and its corresponding // visual layout. Support is built in for a cursor, a selection, simple styling, // complex scripts, and bi-directional text. Implementations provide mechanisms // for rendering and translation between logical and visual data. class UI_EXPORT RenderText { public: virtual ~RenderText(); // Creates a platform-specific RenderText instance. static RenderText* CreateRenderText(); const string16& text() const { return text_; } void SetText(const string16& text); HorizontalAlignment horizontal_alignment() const { return horizontal_alignment_; } void SetHorizontalAlignment(HorizontalAlignment alignment); const FontList& font_list() const { return font_list_; } void SetFontList(const FontList& font_list); // Set the font size to |size| in pixels. void SetFontSize(int size); // Get the first font in |font_list_|. const Font& GetFont() const; bool cursor_enabled() const { return cursor_enabled_; } void SetCursorEnabled(bool cursor_enabled); bool cursor_visible() const { return cursor_visible_; } void set_cursor_visible(bool visible) { cursor_visible_ = visible; } bool insert_mode() const { return insert_mode_; } void ToggleInsertMode(); SkColor cursor_color() const { return cursor_color_; } void set_cursor_color(SkColor color) { cursor_color_ = color; } bool focused() const { return focused_; } void set_focused(bool focused) { focused_ = focused; } const StyleRange& default_style() const { return default_style_; } void set_default_style(const StyleRange& style) { default_style_ = style; } // In an obscured (password) field, all text is drawn as asterisks or bullets. bool is_obscured() const { return obscured_; } void SetObscured(bool obscured); const Rect& display_rect() const { return display_rect_; } void SetDisplayRect(const Rect& r); void set_fade_head(bool fade_head) { fade_head_ = fade_head; } bool fade_head() const { return fade_head_; } void set_fade_tail(bool fade_tail) { fade_tail_ = fade_tail; } bool fade_tail() const { return fade_tail_; } bool background_is_transparent() const { return background_is_transparent_; } void set_background_is_transparent(bool transparent) { background_is_transparent_ = transparent; } const SelectionModel& selection_model() const { return selection_model_; } const ui::Range& selection() const { return selection_model_.selection(); } size_t cursor_position() const { return selection_model_.caret_pos(); } 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. // If |select| is false, the selection start is moved to the same position. void MoveCursor(BreakType break_type, VisualCursorDirection direction, bool select); // 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 MoveCursorTo(const SelectionModel& selection_model); // Move the cursor to the position associated with the clicked point. // If |select| is false, the selection start is moved to the same position. // Returns true if the cursor position or selection range changed. bool MoveCursorTo(const Point& point, bool select); // 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. bool SelectRange(const ui::Range& range); // Returns true if the local point is over selected text. bool IsPointInSelection(const Point& point); // Selects no text, all text, or the word at the current cursor position. void ClearSelection(); void SelectAll(); void SelectWord(); const ui::Range& GetCompositionRange() const; void SetCompositionRange(const ui::Range& composition_range); // Apply |style_range| to the internal style model. void ApplyStyleRange(const StyleRange& style_range); // Apply |default_style_| over the entire text range. void ApplyDefaultStyle(); // Returns the dominant direction of the current text. virtual base::i18n::TextDirection GetTextDirection() = 0; // Returns the visual movement direction corresponding to the logical end // of the text, considering only the dominant direction returned by // |GetTextDirection()|, not the direction of a particular run. VisualCursorDirection GetVisualDirectionOfLogicalEnd(); // Get the size in pixels of the entire string. For the height, this will // return the maximum height among the different fonts in the text runs. // Note that this returns the raw size of the string, which does not include // the margin area of text shadows. virtual Size GetStringSize() = 0; void Draw(Canvas* canvas); // Gets the SelectionModel from a visual point in local coordinates. virtual SelectionModel FindCursorPosition(const Point& point) = 0; // Get the visual bounds of a cursor at |selection|. These bounds typically // represent a vertical line, but if |insert_mode| is true they contain 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. Rect GetCursorBounds(const SelectionModel& selection, 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(); // Given an |index| in text(), return the next or previous grapheme boundary // in logical order (that is, the nearest index for which // |IsCursorablePosition(index)| returns true). 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. virtual size_t IndexOfAdjacentGrapheme(size_t index, LogicalCursorDirection direction) = 0; // 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(); // Sets shadows to drawn with text. void SetTextShadows(const std::vector& shadows); protected: RenderText(); const Point& GetUpdatedDisplayOffset(); void set_cached_bounds_and_offset_valid(bool valid) { cached_bounds_and_offset_valid_ = valid; } const StyleRanges& style_ranges() const { return style_ranges_; } // 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 SelectionModels corresponding to visual text ends. // The returned value represents a cursor/caret position without a selection. SelectionModel EdgeSelectionModel(VisualCursorDirection direction); // Sets the selection model, the argument is assumed to be valid. virtual void SetSelectionModel(const SelectionModel& model); // Get the height and horizontal bounds (relative to the left of the text, not // the view) of the glyph starting at |index|. If the glyph is RTL then // xspan->is_reversed(). This does not return a Rect because a Rect can't have // a negative width. virtual void GetGlyphBounds(size_t index, ui::Range* xspan, int* height) = 0; // Get the visual bounds containing the logical substring within the |range|. // If |range| is empty, the result is empty. 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 longer than the textfield. Subsequent text, cursor, // or bounds changes may invalidate returned values. virtual std::vector GetSubstringBounds(ui::Range range) = 0; // Return true if cursor can appear in front of the character at |position|, // which means it is a grapheme boundary or the first character in the text. virtual bool IsCursorablePosition(size_t position) = 0; // Reset the layout to be invalid. virtual void ResetLayout() = 0; // Ensure the text is laid out. virtual void EnsureLayout() = 0; // Draw the text. virtual void DrawVisualText(Canvas* canvas) = 0; // Like text() except that it returns asterisks or bullets if this is an // obscured field. string16 GetDisplayText() const; // Apply composition style (underline) to composition range and selection // style (foreground) to selection range. void ApplyCompositionAndSelectionStyles(StyleRanges* style_ranges); // Returns the text origin after applying text alignment and display offset. Point GetTextOrigin(); // Convert points from the text space to the view space and back. // Handles the display area, display offset, and the application LTR/RTL mode. Point ToTextPoint(const Point& point); Point ToViewPoint(const Point& point); // Returns the width of content, which reserves room for the cursor if // |cursor_enabled_| is true. int GetContentWidth(); // Returns display offset based on current text alignment. Point GetAlignmentOffset(); // Returns the origin point for drawing text. Does not account for font // baseline, as needed by Skia. Point GetOriginForDrawing(); // Applies fade effects to |renderer|. void ApplyFadeEffects(internal::SkiaTextRenderer* renderer); // Applies text shadows to |renderer|. void ApplyTextShadows(internal::SkiaTextRenderer* renderer); // A convenience function to check whether the glyph attached to the caret // is within the given range. static bool RangeContainsCaret(const ui::Range& range, size_t caret_pos, LogicalCursorDirection caret_affinity); private: friend class RenderTextTest; FRIEND_TEST_ALL_PREFIXES(RenderTextTest, DefaultStyle); FRIEND_TEST_ALL_PREFIXES(RenderTextTest, CustomDefaultStyle); FRIEND_TEST_ALL_PREFIXES(RenderTextTest, ApplyStyleRange); FRIEND_TEST_ALL_PREFIXES(RenderTextTest, StyleRangesAdjust); FRIEND_TEST_ALL_PREFIXES(RenderTextTest, PasswordCensorship); FRIEND_TEST_ALL_PREFIXES(RenderTextTest, GraphemePositions); FRIEND_TEST_ALL_PREFIXES(RenderTextTest, EdgeSelectionModels); FRIEND_TEST_ALL_PREFIXES(RenderTextTest, OriginForDrawing); // Set the cursor to |position|, with the caret trailing the previous // grapheme, or if there is no previous grapheme, leading the cursor position. // If |select| is false, the selection start is moved to the same position. // If the |position| is not a cursorable position (not on grapheme boundary), // it is a NO-OP. void MoveCursorTo(size_t position, bool select); // Update the cached bounds and display offset to ensure that the current // cursor is within the visible display area. void UpdateCachedBoundsAndOffset(); // Draw the selection and cursor. void DrawSelection(Canvas* canvas); void DrawCursor(Canvas* canvas); // Logical UTF-16 string data to be drawn. string16 text_; // Horizontal alignment of the text with respect to |display_rect_|. HorizontalAlignment horizontal_alignment_; // A list of fonts used to render |text_|. FontList font_list_; // Logical selection range 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_; // The cursor visibility and insert mode. bool cursor_visible_; bool insert_mode_; // The color used for the cursor. SkColor cursor_color_; // The focus state of the text. bool focused_; // Composition text range. ui::Range composition_range_; // List of style ranges. Elements in the list never overlap each other. StyleRanges style_ranges_; // The default text style. StyleRange default_style_; // True if this is an obscured (password) field. bool obscured_; // Fade text head and/or tail, if text doesn't fit into |display_rect_|. bool fade_head_; bool fade_tail_; // Is the background transparent (either partially or fully)? bool background_is_transparent_; // The local display area for rendering the text. Rect display_rect_; // The offset for the text to be drawn, relative to the display area. // Get this point with GetUpdatedDisplayOffset (or risk using a stale value). Point display_offset_; // 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_; // Text shadows to be drawn. std::vector text_shadows_; DISALLOW_COPY_AND_ASSIGN(RenderText); }; } // namespace gfx #endif // UI_GFX_RENDER_TEXT_H_