ui/views/controls/button/label_button.h - chromium/src - Git at Google

 // 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_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_

 #include <array>
 #include <memory>

 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/views/controls/button/custom_button.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/native_theme_delegate.h"
 #include "ui/views/style/typography.h"

 namespace views {

 class InkDropContainerView;
 class LabelButtonBorder;
 class Painter;

 // LabelButton is a button with text and an icon, it's not focusable by default.
 class VIEWS_EXPORT LabelButton : public CustomButton,
                                  public NativeThemeDelegate {
  public:
   // The length of the hover fade animation.
   static const int kHoverAnimationDurationMs;

   static const char kViewClassName[];

   // Creates a LabelButton with ButtonPressed() events sent to |listener| and
   // label |text|. |button_context| is a value from views::style::TextContext
   // and determines the appearance of |text|.
   LabelButton(ButtonListener* listener,
               const base::string16& text,
               int button_context = style::CONTEXT_BUTTON);
   ~LabelButton() override;

   // Gets or sets the image shown for the specified button state.
   // GetImage returns the image for STATE_NORMAL if the state's image is empty.
   virtual gfx::ImageSkia GetImage(ButtonState for_state) const;
   void SetImage(ButtonState for_state, const gfx::ImageSkia& image);

   // Gets or sets the text shown on the button.
   const base::string16& GetText() const;
   virtual void SetText(const base::string16& text);

   // Sets the text color shown for the specified button |for_state| to |color|.
   void SetTextColor(ButtonState for_state, SkColor color);

   // Sets the text colors shown for the non-disabled states to |color|.
   virtual void SetEnabledTextColors(SkColor color);

   // Sets drop shadows underneath the text.
   void SetTextShadows(const gfx::ShadowValues& shadows);

   // Sets whether subpixel rendering is used on the label.
   void SetTextSubpixelRenderingEnabled(bool enabled);

   // Sets the elide behavior of this button.
   void SetElideBehavior(gfx::ElideBehavior elide_behavior);

   // Sets the horizontal alignment used for the button; reversed in RTL. The
   // optional image will lead the text, unless the button is right-aligned.
   void SetHorizontalAlignment(gfx::HorizontalAlignment alignment);

   // Call SetMinSize(gfx::Size()) to clear the monotonically increasing size.
   void SetMinSize(const gfx::Size& min_size);
   void SetMaxSize(const gfx::Size& max_size);

   // Gets or sets the option to handle the return key; false by default.
   bool is_default() const { return is_default_; }
   void SetIsDefault(bool is_default);

   // Gets or sets the button's overall style; the default is |STYLE_TEXTBUTTON|.
   // DEPRECATED: ButtonStyle is deprecated. Use MdTextButton in place of
   // |STYLE_BUTTON|.
   ButtonStyle style() const { return style_; }
   void SetStyleDeprecated(ButtonStyle style);

   // Sets the spacing between the image and the text. Shrinking the spacing
   // will not shrink the overall button size, as it is monotonically increasing.
   // Call SetMinSize(gfx::Size()) to clear the size if needed.
   void SetImageLabelSpacing(int spacing);

   void SetFocusPainter(std::unique_ptr<Painter> focus_painter);
   Painter* focus_painter() { return focus_painter_.get(); }

   // Creates the default border for this button. This can be overridden by
   // subclasses.
   virtual std::unique_ptr<LabelButtonBorder> CreateDefaultBorder() const;

   // View:
   void SetBorder(std::unique_ptr<Border> border) override;
   gfx::Size GetPreferredSize() const override;
   int GetHeightForWidth(int w) const override;
   void Layout() override;
   const char* GetClassName() const override;
   void EnableCanvasFlippingForRTLUI(bool flip) override;
   void AddInkDropLayer(ui::Layer* ink_drop_layer) override;
   void RemoveInkDropLayer(ui::Layer* ink_drop_layer) override;
   std::unique_ptr<InkDrop> CreateInkDrop() override;
   std::unique_ptr<InkDropRipple> CreateInkDropRipple() const override;
   std::unique_ptr<InkDropHighlight> CreateInkDropHighlight() const override;

  protected:
   ImageView* image() const { return image_; }
   Label* label() const { return label_; }
   InkDropContainerView* ink_drop_container() const {
     return ink_drop_container_;
   }

   bool explicitly_set_normal_color() const {
     return explicitly_set_colors_[STATE_NORMAL];
   }

   // Returns the available area for the label and image. Subclasses can change
   // these bounds if they need room to do manual painting.
   virtual gfx::Rect GetChildAreaBounds();

   // Returns true if the CreateInkDrop*() methods should create flood fill ink
   // drop components.
   virtual bool ShouldUseFloodFillInkDrop() const;

   // View:
   void OnPaint(gfx::Canvas* canvas) override;
   void OnFocus() override;
   void OnBlur() override;
   void OnNativeThemeChanged(const ui::NativeTheme* theme) override;

   // CustomButton:
   void StateChanged(ButtonState old_state) override;

   // Fills |params| with information about the button.
   virtual void GetExtraParams(ui::NativeTheme::ExtraParams* params) const;

   // Resets colors from the NativeTheme, explicitly set colors are unchanged.
   virtual void ResetColorsFromNativeTheme();

   // Changes the visual styling of this button to reflect the state of
   // |is_default()|.
   virtual void UpdateStyleToIndicateDefaultStatus();

   // Updates the image view to contain the appropriate button state image.
   void UpdateImage();

   // Updates the border as per the NativeTheme, unless a different border was
   // set with SetBorder.
   void UpdateThemedBorder();

   // NativeThemeDelegate:
   gfx::Rect GetThemePaintRect() const override;

   const std::array<bool, STATE_COUNT>& explicitly_set_colors() const {
     return explicitly_set_colors_;
   }
   void set_explicitly_set_colors(const std::array<bool, STATE_COUNT>& colors) {
     explicitly_set_colors_ = colors;
   }

  private:
   void SetTextInternal(const base::string16& text);

   // View:
   void ChildPreferredSizeChanged(View* child) override;

   // NativeThemeDelegate:
   ui::NativeTheme::Part GetThemePart() const override;
   ui::NativeTheme::State GetThemeState(
       ui::NativeTheme::ExtraParams* params) const override;
   const gfx::Animation* GetThemeAnimation() const override;
   ui::NativeTheme::State GetBackgroundThemeState(
       ui::NativeTheme::ExtraParams* params) const override;
   ui::NativeTheme::State GetForegroundThemeState(
       ui::NativeTheme::ExtraParams* params) const override;

   // Resets |cached_preferred_size_| and marks |cached_preferred_size_valid_|
   // as false.
   void ResetCachedPreferredSize();

   // Updates additional state related to focus or default status, rather than
   // merely the CustomButton::state(). E.g. ensures the label text color is
   // correct for the current background.
   void ResetLabelEnabledColor();

   // The image and label shown in the button.
   ImageView* image_;
   Label* label_;

   // A separate view is necessary to hold the ink drop layer so that it can
   // be stacked below |image_| and on top of |label_|, without resorting to
   // drawing |label_| on a layer (which can mess with subpixel anti-aliasing).
   InkDropContainerView* ink_drop_container_;

   // The cached font lists in the normal and default button style. The latter
   // may be bold.
   gfx::FontList cached_normal_font_list_;
   gfx::FontList cached_default_button_font_list_;

   // The images and colors for each button state.
   gfx::ImageSkia button_state_images_[STATE_COUNT];
   SkColor button_state_colors_[STATE_COUNT];

   // Used to track whether SetTextColor() has been invoked.
   std::array<bool, STATE_COUNT> explicitly_set_colors_;

   // |min_size_| increases monotonically with the preferred size.
   mutable gfx::Size min_size_;
   // |max_size_| may be set to clamp the preferred size.
   gfx::Size max_size_;

   // Cache the last computed preferred size.
   mutable gfx::Size cached_preferred_size_;
   mutable bool cached_preferred_size_valid_;

   // Flag indicating default handling of the return key via an accelerator.
   // Whether or not the button appears or behaves as the default button in its
   // current context;
   bool is_default_;

   // The button's overall style.
   ButtonStyle style_;

   // True if current border was set by UpdateThemedBorder. Defaults to true.
   bool border_is_themed_border_;

   // Spacing between the image and the text.
   int image_label_spacing_;

   // Alignment of the button. This can be different from the alignment of the
   // text; for example, the label may be set to ALIGN_TO_HEAD (alignment matches
   // text direction) while |this| is laid out as ALIGN_LEFT (alignment matches
   // UI direction).
   gfx::HorizontalAlignment horizontal_alignment_;

   std::unique_ptr<Painter> focus_painter_;

   DISALLOW_COPY_AND_ASSIGN(LabelButton);
 };

 }  // namespace views

 #endif  // UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_
	// 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_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_
	#define UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_

	#include <array>
	#include <memory>

	#include "base/compiler_specific.h"
	#include "base/gtest_prod_util.h"
	#include "base/macros.h"
	#include "third_party/skia/include/core/SkColor.h"
	#include "ui/gfx/image/image_skia.h"
	#include "ui/views/controls/button/custom_button.h"
	#include "ui/views/controls/image_view.h"
	#include "ui/views/controls/label.h"
	#include "ui/views/native_theme_delegate.h"
	#include "ui/views/style/typography.h"

	namespace views {

	class InkDropContainerView;
	class LabelButtonBorder;
	class Painter;

	// LabelButton is a button with text and an icon, it's not focusable by default.
	class VIEWS_EXPORT LabelButton : public CustomButton,
	public NativeThemeDelegate {
	public:
	// The length of the hover fade animation.
	static const int kHoverAnimationDurationMs;

	static const char kViewClassName[];

	// Creates a LabelButton with ButtonPressed() events sent to \|listener\| and
	// label \|text\|. \|button_context\| is a value from views::style::TextContext
	// and determines the appearance of \|text\|.
	LabelButton(ButtonListener* listener,
	const base::string16& text,
	int button_context = style::CONTEXT_BUTTON);
	~LabelButton() override;

	// Gets or sets the image shown for the specified button state.
	// GetImage returns the image for STATE_NORMAL if the state's image is empty.
	virtual gfx::ImageSkia GetImage(ButtonState for_state) const;
	void SetImage(ButtonState for_state, const gfx::ImageSkia& image);

	// Gets or sets the text shown on the button.
	const base::string16& GetText() const;
	virtual void SetText(const base::string16& text);

	// Sets the text color shown for the specified button \|for_state\| to \|color\|.
	void SetTextColor(ButtonState for_state, SkColor color);

	// Sets the text colors shown for the non-disabled states to \|color\|.
	virtual void SetEnabledTextColors(SkColor color);

	// Sets drop shadows underneath the text.
	void SetTextShadows(const gfx::ShadowValues& shadows);

	// Sets whether subpixel rendering is used on the label.
	void SetTextSubpixelRenderingEnabled(bool enabled);

	// Sets the elide behavior of this button.
	void SetElideBehavior(gfx::ElideBehavior elide_behavior);

	// Sets the horizontal alignment used for the button; reversed in RTL. The
	// optional image will lead the text, unless the button is right-aligned.
	void SetHorizontalAlignment(gfx::HorizontalAlignment alignment);

	// Call SetMinSize(gfx::Size()) to clear the monotonically increasing size.
	void SetMinSize(const gfx::Size& min_size);
	void SetMaxSize(const gfx::Size& max_size);

	// Gets or sets the option to handle the return key; false by default.
	bool is_default() const { return is_default_; }
	void SetIsDefault(bool is_default);

	// Gets or sets the button's overall style; the default is \|STYLE_TEXTBUTTON\|.
	// DEPRECATED: ButtonStyle is deprecated. Use MdTextButton in place of
	// \|STYLE_BUTTON\|.
	ButtonStyle style() const { return style_; }
	void SetStyleDeprecated(ButtonStyle style);

	// Sets the spacing between the image and the text. Shrinking the spacing
	// will not shrink the overall button size, as it is monotonically increasing.
	// Call SetMinSize(gfx::Size()) to clear the size if needed.
	void SetImageLabelSpacing(int spacing);

	void SetFocusPainter(std::unique_ptr<Painter> focus_painter);
	Painter* focus_painter() { return focus_painter_.get(); }

	// Creates the default border for this button. This can be overridden by
	// subclasses.
	virtual std::unique_ptr<LabelButtonBorder> CreateDefaultBorder() const;

	// View:
	void SetBorder(std::unique_ptr<Border> border) override;
	gfx::Size GetPreferredSize() const override;
	int GetHeightForWidth(int w) const override;
	void Layout() override;
	const char* GetClassName() const override;
	void EnableCanvasFlippingForRTLUI(bool flip) override;
	void AddInkDropLayer(ui::Layer* ink_drop_layer) override;
	void RemoveInkDropLayer(ui::Layer* ink_drop_layer) override;
	std::unique_ptr<InkDrop> CreateInkDrop() override;
	std::unique_ptr<InkDropRipple> CreateInkDropRipple() const override;
	std::unique_ptr<InkDropHighlight> CreateInkDropHighlight() const override;

	protected:
	ImageView* image() const { return image_; }
	Label* label() const { return label_; }
	InkDropContainerView* ink_drop_container() const {
	return ink_drop_container_;
	}

	bool explicitly_set_normal_color() const {
	return explicitly_set_colors_[STATE_NORMAL];
	}

	// Returns the available area for the label and image. Subclasses can change
	// these bounds if they need room to do manual painting.
	virtual gfx::Rect GetChildAreaBounds();

	// Returns true if the CreateInkDrop*() methods should create flood fill ink
	// drop components.
	virtual bool ShouldUseFloodFillInkDrop() const;

	// View:
	void OnPaint(gfx::Canvas* canvas) override;
	void OnFocus() override;
	void OnBlur() override;
	void OnNativeThemeChanged(const ui::NativeTheme* theme) override;

	// CustomButton:
	void StateChanged(ButtonState old_state) override;

	// Fills \|params\| with information about the button.
	virtual void GetExtraParams(ui::NativeTheme::ExtraParams* params) const;

	// Resets colors from the NativeTheme, explicitly set colors are unchanged.
	virtual void ResetColorsFromNativeTheme();

	// Changes the visual styling of this button to reflect the state of
	// \|is_default()\|.
	virtual void UpdateStyleToIndicateDefaultStatus();

	// Updates the image view to contain the appropriate button state image.
	void UpdateImage();

	// Updates the border as per the NativeTheme, unless a different border was
	// set with SetBorder.
	void UpdateThemedBorder();

	// NativeThemeDelegate:
	gfx::Rect GetThemePaintRect() const override;

	const std::array<bool, STATE_COUNT>& explicitly_set_colors() const {
	return explicitly_set_colors_;
	}
	void set_explicitly_set_colors(const std::array<bool, STATE_COUNT>& colors) {
	explicitly_set_colors_ = colors;
	}

	private:
	void SetTextInternal(const base::string16& text);

	// View:
	void ChildPreferredSizeChanged(View* child) override;

	// NativeThemeDelegate:
	ui::NativeTheme::Part GetThemePart() const override;
	ui::NativeTheme::State GetThemeState(
	ui::NativeTheme::ExtraParams* params) const override;
	const gfx::Animation* GetThemeAnimation() const override;
	ui::NativeTheme::State GetBackgroundThemeState(
	ui::NativeTheme::ExtraParams* params) const override;
	ui::NativeTheme::State GetForegroundThemeState(
	ui::NativeTheme::ExtraParams* params) const override;

	// Resets \|cached_preferred_size_\| and marks \|cached_preferred_size_valid_\|
	// as false.
	void ResetCachedPreferredSize();

	// Updates additional state related to focus or default status, rather than
	// merely the CustomButton::state(). E.g. ensures the label text color is
	// correct for the current background.
	void ResetLabelEnabledColor();

	// The image and label shown in the button.
	ImageView* image_;
	Label* label_;

	// A separate view is necessary to hold the ink drop layer so that it can
	// be stacked below \|image_\| and on top of \|label_\|, without resorting to
	// drawing \|label_\| on a layer (which can mess with subpixel anti-aliasing).
	InkDropContainerView* ink_drop_container_;

	// The cached font lists in the normal and default button style. The latter
	// may be bold.
	gfx::FontList cached_normal_font_list_;
	gfx::FontList cached_default_button_font_list_;

	// The images and colors for each button state.
	gfx::ImageSkia button_state_images_[STATE_COUNT];
	SkColor button_state_colors_[STATE_COUNT];

	// Used to track whether SetTextColor() has been invoked.
	std::array<bool, STATE_COUNT> explicitly_set_colors_;

	// \|min_size_\| increases monotonically with the preferred size.
	mutable gfx::Size min_size_;
	// \|max_size_\| may be set to clamp the preferred size.
	gfx::Size max_size_;

	// Cache the last computed preferred size.
	mutable gfx::Size cached_preferred_size_;
	mutable bool cached_preferred_size_valid_;

	// Flag indicating default handling of the return key via an accelerator.
	// Whether or not the button appears or behaves as the default button in its
	// current context;
	bool is_default_;

	// The button's overall style.
	ButtonStyle style_;

	// True if current border was set by UpdateThemedBorder. Defaults to true.
	bool border_is_themed_border_;

	// Spacing between the image and the text.
	int image_label_spacing_;

	// Alignment of the button. This can be different from the alignment of the
	// text; for example, the label may be set to ALIGN_TO_HEAD (alignment matches
	// text direction) while \|this\| is laid out as ALIGN_LEFT (alignment matches
	// UI direction).
	gfx::HorizontalAlignment horizontal_alignment_;

	std::unique_ptr<Painter> focus_painter_;

	DISALLOW_COPY_AND_ASSIGN(LabelButton);
	};

	} // namespace views

	#endif // UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_