ui/views/controls/button/label

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This source file includes following definitions.
style_
GetImage
SetImage
GetText
SetText
SetTextColor
GetTextMultiLine
SetTextMultiLine
GetFontList
SetFontList
SetElideBehavior
GetHorizontalAlignment
SetHorizontalAlignment
SetIsDefault
SetStyle
SetFocusPainter
GetPreferredSize
Layout
GetClassName
OnPaint
OnFocus
OnBlur
GetExtraParams
ResetColorsFromNativeTheme
UpdateImage
UpdateThemedBorder
StateChanged
ChildPreferredSizeChanged
OnNativeThemeChanged
GetThemePart
GetThemePaintRect
GetThemeState
GetThemeAnimation
GetBackgroundThemeState
GetForegroundThemeState
// 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.

#include "ui/views/controls/button/label_button.h"

#include "base/logging.h"
#include "grit/ui_resources.h"
#include "ui/base/resource/resource_bundle.h"
#include "ui/gfx/animation/throb_animation.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/font_list.h"
#include "ui/gfx/sys_color_change_listener.h"
#include "ui/native_theme/native_theme.h"
#include "ui/views/background.h"
#include "ui/views/controls/button/label_button_border.h"
#include "ui/views/painter.h"
#include "ui/views/window/dialog_delegate.h"

#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
#include "ui/views/linux_ui/linux_ui.h"
#endif

namespace {

// The spacing between the icon and text.
const int kSpacing = 5;

#if !(defined(OS_LINUX) && !defined(OS_CHROMEOS))
// Default text and shadow colors for STYLE_BUTTON.
const SkColor kStyleButtonTextColor = SK_ColorBLACK;
const SkColor kStyleButtonShadowColor = SK_ColorWHITE;
#endif

}  // namespace

namespace views {

// static
const int LabelButton::kHoverAnimationDurationMs = 170;

// static
const char LabelButton::kViewClassName[] = "LabelButton";

LabelButton::LabelButton(ButtonListener* listener, const base::string16& text)
    : CustomButton(listener),
      image_(new ImageView()),
      label_(new Label()),
      button_state_images_(),
      button_state_colors_(),
      explicitly_set_colors_(),
      is_default_(false),
      style_(STYLE_TEXTBUTTON) {
  SetAnimationDuration(kHoverAnimationDurationMs);
  SetText(text);
  SetFontList(gfx::FontList());

  AddChildView(image_);
  image_->set_interactive(false);

  AddChildView(label_);
  label_->SetAutoColorReadabilityEnabled(false);
  label_->SetHorizontalAlignment(gfx::ALIGN_LEFT);

  // Initialize the colors, border, and layout.
  SetStyle(style_);

  SetAccessibleName(text);
}

LabelButton::~LabelButton() {}

const gfx::ImageSkia& LabelButton::GetImage(ButtonState for_state) {
  if (for_state != STATE_NORMAL && button_state_images_[for_state].isNull())
    return button_state_images_[STATE_NORMAL];
  return button_state_images_[for_state];
}

void LabelButton::SetImage(ButtonState for_state, const gfx::ImageSkia& image) {
  button_state_images_[for_state] = image;
  UpdateImage();
}

const base::string16& LabelButton::GetText() const {
  return label_->text();
}

void LabelButton::SetText(const base::string16& text) {
  SetAccessibleName(text);
  label_->SetText(text);
}

void LabelButton::SetTextColor(ButtonState for_state, SkColor color) {
  button_state_colors_[for_state] = color;
  if (for_state == STATE_DISABLED)
    label_->SetDisabledColor(color);
  else if (for_state == state())
    label_->SetEnabledColor(color);
  explicitly_set_colors_[for_state] = true;
}

bool LabelButton::GetTextMultiLine() const {
  return label_->is_multi_line();
}

void LabelButton::SetTextMultiLine(bool text_multi_line) {
  label_->SetMultiLine(text_multi_line);
}

const gfx::FontList& LabelButton::GetFontList() const {
  return label_->font_list();
}

void LabelButton::SetFontList(const gfx::FontList& font_list) {
  cached_normal_font_list_ = font_list;
  cached_bold_font_list_ = font_list.DeriveWithStyle(
      font_list.GetFontStyle() | gfx::Font::BOLD);

  // STYLE_BUTTON uses bold text to indicate default buttons.
  label_->SetFontList(
      style_ == STYLE_BUTTON && is_default_ ?
      cached_bold_font_list_ : cached_normal_font_list_);
}

void LabelButton::SetElideBehavior(Label::ElideBehavior elide_behavior) {
  label_->SetElideBehavior(elide_behavior);
}

gfx::HorizontalAlignment LabelButton::GetHorizontalAlignment() const {
  return label_->horizontal_alignment();
}

void LabelButton::SetHorizontalAlignment(gfx::HorizontalAlignment alignment) {
  label_->SetHorizontalAlignment(alignment);
  InvalidateLayout();
}

void LabelButton::SetIsDefault(bool is_default) {
  if (is_default == is_default_)
    return;
  is_default_ = is_default;
  ui::Accelerator accel(ui::VKEY_RETURN, ui::EF_NONE);
  is_default_ ? AddAccelerator(accel) : RemoveAccelerator(accel);

  // STYLE_BUTTON uses bold text to indicate default buttons.
  if (style_ == STYLE_BUTTON) {
    label_->SetFontList(
        is_default ? cached_bold_font_list_ : cached_normal_font_list_);
  }
}

void LabelButton::SetStyle(ButtonStyle style) {
  style_ = style;
  // Inset the button focus rect from the actual border; roughly match Windows.
  if (style == STYLE_BUTTON) {
    SetFocusPainter(scoped_ptr<Painter>());
  } else {
    SetFocusPainter(Painter::CreateDashedFocusPainterWithInsets(
                        gfx::Insets(3, 3, 3, 3)));
  }
  if (style == STYLE_BUTTON) {
    label_->SetHorizontalAlignment(gfx::ALIGN_CENTER);
    SetFocusable(true);
  }
  if (style == STYLE_BUTTON)
    set_min_size(gfx::Size(70, 33));

  ResetColorsFromNativeTheme();

  UpdateThemedBorder(scoped_ptr<Border>(new LabelButtonBorder(style_)));

  // Invalidate the layout to pickup the new insets from the border.
  InvalidateLayout();
}

void LabelButton::SetFocusPainter(scoped_ptr<Painter> focus_painter) {
  focus_painter_ = focus_painter.Pass();
}

gfx::Size LabelButton::GetPreferredSize() {
  // Use a temporary label copy for sizing to avoid calculation side-effects.
  Label label(GetText(), cached_normal_font_list_);
  label.SetMultiLine(GetTextMultiLine());

  if (style() == STYLE_BUTTON) {
    // Some text appears wider when rendered normally than when rendered bold.
    // Accommodate the widest, as buttons may show bold and shouldn't resize.
    const int current_width = label.GetPreferredSize().width();
    label.SetFontList(cached_bold_font_list_);
    if (label.GetPreferredSize().width() < current_width)
      label.SetFontList(cached_normal_font_list_);
  }

  // Resize multi-line labels given the current limited available width.
  const gfx::Size image_size(image_->GetPreferredSize());
  const int image_width = image_size.width();
  if (GetTextMultiLine() && (width() > image_width + kSpacing))
    label.SizeToFit(width() - image_width - (image_width > 0 ? kSpacing : 0));

  // Calculate the required size.
  gfx::Size size(label.GetPreferredSize());
  if (image_width > 0 && size.width() > 0)
    size.Enlarge(kSpacing, 0);
  size.SetToMax(gfx::Size(0, image_size.height()));
  const gfx::Insets insets(GetInsets());
  size.Enlarge(image_size.width() + insets.width(), insets.height());

  // Make the size at least as large as the minimum size needed by the border.
  size.SetToMax(border() ? border()->GetMinimumSize() : gfx::Size());

  // Increase the minimum size monotonically with the preferred size.
  size.SetToMax(min_size_);
  min_size_ = size;

  // Return the largest known size clamped to the maximum size (if valid).
  if (max_size_.width() > 0)
    size.set_width(std::min(max_size_.width(), size.width()));
  if (max_size_.height() > 0)
    size.set_height(std::min(max_size_.height(), size.height()));
  return size;
}

void LabelButton::Layout() {
  gfx::HorizontalAlignment adjusted_alignment = GetHorizontalAlignment();
  if (base::i18n::IsRTL() && adjusted_alignment != gfx::ALIGN_CENTER)
    adjusted_alignment = (adjusted_alignment == gfx::ALIGN_LEFT) ?
        gfx::ALIGN_RIGHT : gfx::ALIGN_LEFT;

  gfx::Rect child_area(GetLocalBounds());
  child_area.Inset(GetInsets());

  gfx::Size image_size(image_->GetPreferredSize());
  image_size.SetToMin(child_area.size());

  // The label takes any remaining width after sizing the image, unless both
  // views are centered. In that case, using the tighter preferred label width
  // avoids wasted space within the label that would look like awkward padding.
  gfx::Size label_size(child_area.size());
  if (!image_size.IsEmpty() && !label_size.IsEmpty()) {
    label_size.set_width(
        std::max(child_area.width() - image_size.width() - kSpacing, 0));
    if (adjusted_alignment == gfx::ALIGN_CENTER) {
      // Ensure multi-line labels paired with images use their available width.
      if (GetTextMultiLine())
        label_->SizeToFit(label_size.width());
      label_size.set_width(
          std::min(label_size.width(), label_->GetPreferredSize().width()));
    }
  }

  gfx::Point image_origin(child_area.origin());
  image_origin.Offset(0, (child_area.height() - image_size.height()) / 2);
  if (adjusted_alignment == gfx::ALIGN_CENTER) {
    const int total_width = image_size.width() + label_size.width() +
        ((image_size.width() > 0 && label_size.width() > 0) ? kSpacing : 0);
    image_origin.Offset((child_area.width() - total_width) / 2, 0);
  } else if (adjusted_alignment == gfx::ALIGN_RIGHT) {
    image_origin.Offset(child_area.width() - image_size.width(), 0);
  }

  gfx::Point label_origin(child_area.origin());
  if (!image_size.IsEmpty() &&adjusted_alignment != gfx::ALIGN_RIGHT)
    label_origin.set_x(image_origin.x() + image_size.width() + kSpacing);

  image_->SetBoundsRect(gfx::Rect(image_origin, image_size));
  label_->SetBoundsRect(gfx::Rect(label_origin, label_size));
}

const char* LabelButton::GetClassName() const {
  return kViewClassName;
}

void LabelButton::OnPaint(gfx::Canvas* canvas) {
  View::OnPaint(canvas);
  Painter::PaintFocusPainter(this, canvas, focus_painter_.get());
}

void LabelButton::OnFocus() {
  View::OnFocus();
  // Typically the border renders differently when focused.
  SchedulePaint();
}

void LabelButton::OnBlur() {
  View::OnBlur();
  // Typically the border renders differently when focused.
  SchedulePaint();
}

void LabelButton::GetExtraParams(ui::NativeTheme::ExtraParams* params) const {
  params->button.checked = false;
  params->button.indeterminate = false;
  params->button.is_default = is_default_;
  params->button.is_focused = HasFocus() && IsAccessibilityFocusable();
  params->button.has_border = false;
  params->button.classic_state = 0;
  params->button.background_color = label_->background_color();
}

void LabelButton::ResetColorsFromNativeTheme() {
  const ui::NativeTheme* theme = GetNativeTheme();
  SkColor colors[STATE_COUNT] = {
    theme->GetSystemColor(ui::NativeTheme::kColorId_ButtonEnabledColor),
    theme->GetSystemColor(ui::NativeTheme::kColorId_ButtonHoverColor),
    theme->GetSystemColor(ui::NativeTheme::kColorId_ButtonHoverColor),
    theme->GetSystemColor(ui::NativeTheme::kColorId_ButtonDisabledColor),
  };

  // Certain styles do not change text color when hovered or pressed.
  bool constant_text_color = false;
  // Use hardcoded colors for inverted color scheme support and STYLE_BUTTON.
  if (gfx::IsInvertedColorScheme()) {
    constant_text_color = true;
    colors[STATE_NORMAL] = SK_ColorWHITE;
    label_->SetBackgroundColor(SK_ColorBLACK);
    label_->set_background(Background::CreateSolidBackground(SK_ColorBLACK));
    label_->SetAutoColorReadabilityEnabled(true);
    label_->ClearEmbellishing();
  } else if (style() == STYLE_BUTTON) {
    // TODO(erg): This is disabled on desktop linux because of the binary asset
    // confusion. These details should either be pushed into ui::NativeThemeWin
    // or should be obsoleted by rendering buttons with paint calls instead of
    // with static assets. http://crbug.com/350498
#if !(defined(OS_LINUX) && !defined(OS_CHROMEOS))
    constant_text_color = true;
    colors[STATE_NORMAL] = kStyleButtonTextColor;
    label_->SetBackgroundColor(theme->GetSystemColor(
        ui::NativeTheme::kColorId_ButtonBackgroundColor));
    label_->SetAutoColorReadabilityEnabled(false);
    label_->SetShadowColors(kStyleButtonShadowColor, kStyleButtonShadowColor);
    label_->SetShadowOffset(0, 1);
#endif
    label_->set_background(NULL);
  } else {
    label_->set_background(NULL);
  }

  if (constant_text_color)
    colors[STATE_HOVERED] = colors[STATE_PRESSED] = colors[STATE_NORMAL];

  for (size_t state = STATE_NORMAL; state < STATE_COUNT; ++state) {
    if (!explicitly_set_colors_[state]) {
      SetTextColor(static_cast<ButtonState>(state), colors[state]);
      explicitly_set_colors_[state] = false;
    }
  }
}

void LabelButton::UpdateImage() {
  image_->SetImage(GetImage(state()));
}

void LabelButton::UpdateThemedBorder(scoped_ptr<Border> label_button_border) {
#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
  views::LinuxUI* linux_ui = views::LinuxUI::instance();
  if (linux_ui) {
    SetBorder(linux_ui->CreateNativeBorder(this, label_button_border.Pass()));
  } else
#endif
  {
    SetBorder(label_button_border.Pass());
  }
}

void LabelButton::StateChanged() {
  const gfx::Size previous_image_size(image_->GetPreferredSize());
  UpdateImage();
  const SkColor color = button_state_colors_[state()];
  if (state() != STATE_DISABLED && label_->enabled_color() != color)
    label_->SetEnabledColor(color);
  label_->SetEnabled(state() != STATE_DISABLED);
  if (image_->GetPreferredSize() != previous_image_size)
    Layout();
}

void LabelButton::ChildPreferredSizeChanged(View* child) {
  PreferredSizeChanged();
}

void LabelButton::OnNativeThemeChanged(const ui::NativeTheme* theme) {
  ResetColorsFromNativeTheme();
}

ui::NativeTheme::Part LabelButton::GetThemePart() const {
  return ui::NativeTheme::kPushButton;
}

gfx::Rect LabelButton::GetThemePaintRect() const {
  return GetLocalBounds();
}

ui::NativeTheme::State LabelButton::GetThemeState(
    ui::NativeTheme::ExtraParams* params) const {
  GetExtraParams(params);
  switch (state()) {
    case STATE_NORMAL:   return ui::NativeTheme::kNormal;
    case STATE_HOVERED:  return ui::NativeTheme::kHovered;
    case STATE_PRESSED:  return ui::NativeTheme::kPressed;
    case STATE_DISABLED: return ui::NativeTheme::kDisabled;
    case STATE_COUNT:    NOTREACHED() << "Unknown state: " << state();
  }
  return ui::NativeTheme::kNormal;
}

const gfx::Animation* LabelButton::GetThemeAnimation() const {
  return hover_animation_.get();
}

ui::NativeTheme::State LabelButton::GetBackgroundThemeState(
    ui::NativeTheme::ExtraParams* params) const {
  GetExtraParams(params);
  return ui::NativeTheme::kNormal;
}

ui::NativeTheme::State LabelButton::GetForegroundThemeState(
    ui::NativeTheme::ExtraParams* params) const {
  GetExtraParams(params);
  return ui::NativeTheme::kHovered;
}

}  // namespace views
/* [<][>][^][v][top][bottom][index][help] */
root/ui/views/controls/button/label_button.cc

DEFINITIONS
