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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_FONT_LIST_H_
- #define UI_GFX_FONT_LIST_H_
- #include <string>
- #include <vector>
- #include "base/memory/ref_counted.h"
- #include "ui/gfx/font.h"
- #include "ui/gfx/gfx_export.h"
- namespace gfx {
- class FontListImpl;
- // FontList represents a list of fonts and provides metrics which are common
- // across the fonts. FontList is copyable and quite cheap to copy.
- //
- // The format of font description strings is a subset of that used by Pango, as
- // described at
- // http://developer.gnome.org/pango/stable/pango-Fonts.html#pango-font-description-from-string
- //
- // Pango font description strings should not be passed directly into FontLists.
- //
- // The format is "<FONT_FAMILY_LIST>,[STYLES] <SIZE>", where:
- // - FONT_FAMILY_LIST is a comma-separated list of font family names,
- // - STYLES is an optional space-separated list of style names (case-sensitive
- // "Italic" "Ultra-Light" "Light" "Normal" "Semi-Bold" "Bold" "Ultra-Bold"
- // "Heavy" are supported), and
- // - SIZE is an integer font size in pixels with the suffix "px"
- //
- // Here are examples of valid font description strings:
- // - "Arial, Helvetica, Italic Semi-Bold 14px"
- // - "Arial, 14px"
- class GFX_EXPORT FontList {
- public:
- // Parses a FontList description string into |families_out|, |style_out| (a
- // bitfield of gfx::Font::Style values), |size_pixels_out| and |weight_out|.
- // Returns true if the string is properly-formed.
- static bool ParseDescription(const std::string& description,
- std::vector<std::string>* families_out,
- int* style_out,
- int* size_pixels_out,
- Font::Weight* weight_out);
- // Creates a font list with default font names, size and style, which are
- // specified by SetDefaultFontDescription().
- FontList();
- // Creates a font list that is a clone of another font list.
- FontList(const FontList& other);
- // Creates a font list from a string representing font names, styles, and
- // size.
- explicit FontList(const std::string& font_description_string);
- // Creates a font list from font names, styles, size and weight.
- FontList(const std::vector<std::string>& font_names,
- int font_style,
- int font_size,
- Font::Weight font_weight);
- // Creates a font list from a Font vector.
- // All fonts in this vector should have the same style and size.
- explicit FontList(const std::vector<Font>& fonts);
- // Creates a font list from a Font.
- explicit FontList(const Font& font);
- ~FontList();
- // Copies the given font list into this object.
- FontList& operator=(const FontList& other);
- // Sets the description string for default FontList construction. If it's
- // empty, FontList will initialize using the default Font constructor.
- //
- // The client code must call this function before any call of the default
- // constructor. This should be done on the UI thread.
- //
- // ui::ResourceBundle may call this function more than once when UI language
- // is changed.
- //
- // Unit Tests should use ScopedDefaultFontDescription instead of calling this
- // directly, to avoid leaving the default font description in an unexpected
- // state for tests that run in the same process.
- static void SetDefaultFontDescription(const std::string& font_description);
- // Returns a new FontList with the same font names but resized and the given
- // style and weight. |size_delta| is the size in pixels to add to the current
- // font size. |font_style| specifies the new style, which is a bitmask of the
- // values: Font::ITALIC and Font::UNDERLINE. |weight| is the requested font
- // weight.
- FontList Derive(int size_delta,
- int font_style,
- Font::Weight weight) const;
- // Returns a new FontList with the same font names and style but resized.
- // |size_delta| is the size in pixels to add to the current font size.
- FontList DeriveWithSizeDelta(int size_delta) const;
- // Returns a new FontList with the same font names, weight and size but the
- // given style. |font_style| specifies the new style, which is a bitmask of
- // the values: Font::ITALIC and Font::UNDERLINE.
- FontList DeriveWithStyle(int font_style) const;
- // Returns a new FontList with the same font name, size and style but with
- // the given weight.
- FontList DeriveWithWeight(Font::Weight weight) const;
- // Shrinks the font size until the font list fits within |height| while
- // having its cap height vertically centered. Returns a new FontList with
- // the correct height.
- //
- // The expected layout:
- // +--------+-----------------------------------------------+------------+
- // | | y offset | space |
- // | +--------+-------------------+------------------+ above |
- // | | | | internal leading | cap height |
- // | box | font | ascent (baseline) +------------------+------------+
- // | height | height | | cap height |
- // | | |-------------------+------------------+------------+
- // | | | descent (height - baseline) | space |
- // | +--------+--------------------------------------+ below |
- // | | space at bottom | cap height |
- // +--------+-----------------------------------------------+------------+
- // Goal:
- // center of box height == center of cap height
- // (i.e. space above cap height == space below cap height)
- // Restrictions:
- // y offset >= 0
- // space at bottom >= 0
- // (i.e. Entire font must be visible inside the box.)
- FontList DeriveWithHeightUpperBound(int height) const;
- // Returns the height of this font list, which is max(ascent) + max(descent)
- // for all the fonts in the font list.
- int GetHeight() const;
- // Returns the baseline of this font list, which is max(baseline) for all the
- // fonts in the font list.
- int GetBaseline() const;
- // Returns the cap height of this font list.
- // Currently returns the cap height of the primary font.
- int GetCapHeight() const;
- // Returns the expected number of horizontal pixels needed to display the
- // specified length of characters. Call GetStringWidth() to retrieve the
- // actual number.
- int GetExpectedTextWidth(int length) const;
- // Returns the |Font::FontStyle| style flags for this font list.
- int GetFontStyle() const;
- // Returns the font size in pixels.
- int GetFontSize() const;
- // Returns the font weight.
- Font::Weight GetFontWeight() const;
- // Returns the Font vector.
- const std::vector<Font>& GetFonts() const;
- // Returns the first font in the list.
- const Font& GetPrimaryFont() const;
- // Returns the first available font name. If there is no available font,
- // returns the first font name. Empty entries are ignored.
- // Used by Blink and webui to pick the primary standard/serif/sans/fixed/etc.
- // fonts from region-specific IDS lists.
- static std::string FirstAvailableOrFirst(const std::string& font_name_list);
- private:
- explicit FontList(FontListImpl* impl);
- static const scoped_refptr<FontListImpl>& GetDefaultImpl();
- scoped_refptr<FontListImpl> impl_;
- };
- } // namespace gfx
- #endif // UI_GFX_FONT_LIST_H_
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