// 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 <stddef.h>

#include <utility>

#include "base/lazy_instance.h"
#include "base/logging.h"
#include "build/build_config.h"
#include "ui/gfx/animation/throb_animation.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/color_utils.h"
#include "ui/gfx/font_list.h"
#include "ui/gfx/geometry/vector2d.h"
#include "ui/native_theme/native_theme.h"
#include "ui/views/animation/flood_fill_ink_drop_ripple.h"
#include "ui/views/animation/ink_drop.h"
#include "ui/views/animation/ink_drop_highlight.h"
#include "ui/views/animation/ink_drop_impl.h"
#include "ui/views/animation/square_ink_drop_ripple.h"
#include "ui/views/background.h"
#include "ui/views/controls/button/label_button_border.h"
#include "ui/views/controls/button/label_button_label.h"
#include "ui/views/layout/layout_provider.h"
#include "ui/views/painter.h"
#include "ui/views/style/platform_style.h"
#include "ui/views/window/dialog_delegate.h"

namespace views {

// static
const int LabelButton::kHoverAnimationDurationMs = 170;
const char LabelButton::kViewClassName[] = "LabelButton";

LabelButton::LabelButton(ButtonListener* listener,
                         const base::string16& text,
                         int button_context)
    : Button(listener),
      image_(new ImageView()),
      label_(new LabelButtonLabel(text, button_context)),
      ink_drop_container_(new InkDropContainerView()),
      cached_normal_font_list_(
          style::GetFont(button_context, style::STYLE_PRIMARY)),
      cached_default_button_font_list_(
          style::GetFont(button_context, style::STYLE_DIALOG_BUTTON_DEFAULT)),
      button_state_images_(),
      button_state_colors_(),
      explicitly_set_colors_(),
      is_default_(false),
      style_(STYLE_TEXTBUTTON),
      border_is_themed_border_(true),
      image_label_spacing_(LayoutProvider::Get()->GetDistanceMetric(
          DISTANCE_RELATED_LABEL_HORIZONTAL)),
      horizontal_alignment_(gfx::ALIGN_LEFT) {
  SetAnimationDuration(kHoverAnimationDurationMs);
  SetTextInternal(text);

  AddChildView(ink_drop_container_);
  ink_drop_container_->SetPaintToLayer();
  ink_drop_container_->layer()->SetFillsBoundsOpaquely(false);
  ink_drop_container_->SetVisible(false);

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

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

  // Inset the button focus rect from the actual border; roughly match Windows.
  SetFocusPainter(Painter::CreateDashedFocusPainterWithInsets(gfx::Insets(3)));
}

LabelButton::~LabelButton() {}

gfx::ImageSkia LabelButton::GetImage(ButtonState for_state) const {
  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) {
  SetTextInternal(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;
}

void LabelButton::SetEnabledTextColors(SkColor color) {
  ButtonState states[] = {STATE_NORMAL, STATE_HOVERED, STATE_PRESSED};
  for (auto state : states)
    SetTextColor(state, color);
}

void LabelButton::SetTextShadows(const gfx::ShadowValues& shadows) {
  label_->SetShadows(shadows);
}

void LabelButton::SetTextSubpixelRenderingEnabled(bool enabled) {
  label_->SetSubpixelRenderingEnabled(enabled);
}

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

void LabelButton::SetHorizontalAlignment(gfx::HorizontalAlignment alignment) {
  DCHECK_NE(gfx::ALIGN_TO_HEAD, alignment);
  horizontal_alignment_ = alignment;
  InvalidateLayout();
}

void LabelButton::SetMinSize(const gfx::Size& min_size) {
  min_size_ = min_size;
  ResetCachedPreferredSize();
}

void LabelButton::SetMaxSize(const gfx::Size& max_size) {
  max_size_ = max_size;
  ResetCachedPreferredSize();
}

void LabelButton::SetIsDefault(bool is_default) {
  // TODO(estade): move this to MdTextButton once |style_| is removed.
  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);

  UpdateStyleToIndicateDefaultStatus();
}

void LabelButton::SetStyleDeprecated(ButtonStyle style) {
  // All callers currently pass STYLE_BUTTON, and should only call this once, to
  // change from the default style.
  DCHECK_EQ(style, STYLE_BUTTON);
  DCHECK_EQ(style_, STYLE_TEXTBUTTON);
  DCHECK(!GetWidget()) << "Can't change button style after adding to a Widget.";

  style_ = style;

  SetFocusPainter(nullptr);
  SetHorizontalAlignment(gfx::ALIGN_CENTER);
  SetFocusForPlatform();
  set_request_focus_on_press(true);
  SetMinSize(gfx::Size(PlatformStyle::kMinLabelButtonWidth,
                       PlatformStyle::kMinLabelButtonHeight));

  // Themed borders will be set once the button is added to a Widget, since that
  // provides the value of GetNativeTheme().
}

void LabelButton::SetImageLabelSpacing(int spacing) {
  if (spacing == image_label_spacing_)
    return;
  image_label_spacing_ = spacing;
  ResetCachedPreferredSize();
  InvalidateLayout();
}

gfx::Size LabelButton::CalculatePreferredSize() const {
  if (cached_preferred_size_valid_)
    return cached_preferred_size_;

  // Use a temporary label copy for sizing to avoid calculation side-effects.
  Label label(GetText(), {label_->font_list()});
  label.SetLineHeight(label_->line_height());
  label.SetShadows(label_->shadows());

  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_default_button_font_list_);
    if (label.GetPreferredSize().width() < current_width)
      label.SetFontList(label_->font_list());
  }

  // Calculate the required size.
  const gfx::Size preferred_label_size = label.GetPreferredSize();
  gfx::Size size = GetUnclampedSizeWithoutLabel();
  size.Enlarge(preferred_label_size.width(), 0);

  // Increase the height of the label (with insets) if larger.
  size.set_height(std::max(preferred_label_size.height() + GetInsets().height(),
                           size.height()));

  size.SetToMax(min_size_);

  // Clamp size to max 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()));

  // Cache this computed size, as recomputing it is an expensive operation.
  cached_preferred_size_valid_ = true;
  cached_preferred_size_ = size;
  return cached_preferred_size_;
}

int LabelButton::GetHeightForWidth(int width) const {
  const gfx::Size size_without_label = GetUnclampedSizeWithoutLabel();
  // Get label height for the remaining width.
  const int label_height_with_insets =
      label_->GetHeightForWidth(width - size_without_label.width()) +
      GetInsets().height();

  // Height is the larger of size without label and label height with insets.
  int height = std::max(size_without_label.height(), label_height_with_insets);

  // Make sure height respects min_size_.
  if (height < min_size_.height())
    height = min_size_.height();

  // Clamp height to the maximum height (if valid).
  if (max_size_.height() > 0)
    return std::min(max_size_.height(), height);

  return height;
}

void LabelButton::Layout() {
  ink_drop_container_->SetBoundsRect(GetLocalBounds());

  // By default, GetChildAreaBounds() ignores the top and bottom border, but we
  // want the image to respect it.
  gfx::Rect child_area(GetChildAreaBounds());
  // The space that the label can use. Its actual bounds may be smaller if the
  // label is short.
  gfx::Rect label_area(child_area);

  gfx::Insets insets(GetInsets());
  child_area.Inset(insets);
  // Labels can paint over the vertical component of the border insets.
  label_area.Inset(insets.left(), 0, insets.right(), 0);

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

  if (!image_size.IsEmpty()) {
    int image_space = image_size.width() + image_label_spacing_;
    if (horizontal_alignment_ == gfx::ALIGN_RIGHT)
      label_area.Inset(0, 0, image_space, 0);
    else
      label_area.Inset(image_space, 0, 0, 0);
  }

  gfx::Size label_size(
      std::min(label_area.width(), label_->GetPreferredSize().width()),
      label_area.height());

  gfx::Point image_origin(child_area.origin());
  if (label_->multi_line()) {
    // Right now this code currently only works for CheckBox and RadioButton
    // descendants that have multi-line enabled for their label.
    image_origin.Offset(
        0, std::max(
               0, (label_->font_list().GetHeight() - image_size.height()) / 2));
  } else {
    image_origin.Offset(0, (child_area.height() - image_size.height()) / 2);
  }
  if (horizontal_alignment_ == gfx::ALIGN_CENTER) {
    const int spacing = (image_size.width() > 0 && label_size.width() > 0) ?
        image_label_spacing_ : 0;
    const int total_width = image_size.width() + label_size.width() +
        spacing;
    image_origin.Offset((child_area.width() - total_width) / 2, 0);
  } else if (horizontal_alignment_ == gfx::ALIGN_RIGHT) {
    image_origin.Offset(child_area.width() - image_size.width(), 0);
  }
  image_->SetBoundsRect(gfx::Rect(image_origin, image_size));

  gfx::Rect label_bounds = label_area;
  if (label_area.width() == label_size.width()) {
    // Label takes up the whole area.
  } else if (horizontal_alignment_ == gfx::ALIGN_CENTER) {
    label_bounds.ClampToCenteredSize(label_size);
  } else {
    label_bounds.set_size(label_size);
    if (horizontal_alignment_ == gfx::ALIGN_RIGHT)
      label_bounds.Offset(label_area.width() - label_size.width(), 0);
  }

  label_->SetBoundsRect(label_bounds);
  Button::Layout();
}

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

void LabelButton::EnableCanvasFlippingForRTLUI(bool flip) {
  Button::EnableCanvasFlippingForRTLUI(flip);
  image_->EnableCanvasFlippingForRTLUI(flip);
}

std::unique_ptr<LabelButtonBorder> LabelButton::CreateDefaultBorder() const {
  if (style_ != Button::STYLE_TEXTBUTTON)
    return std::make_unique<LabelButtonAssetBorder>(style_);
  std::unique_ptr<LabelButtonBorder> border =
      std::make_unique<LabelButtonBorder>();
  border->set_insets(views::LabelButtonAssetBorder::GetDefaultInsetsForStyle(
      style_));
  return border;
}

void LabelButton::SetBorder(std::unique_ptr<Border> border) {
  border_is_themed_border_ = false;
  View::SetBorder(std::move(border));
  ResetCachedPreferredSize();
}

Label* LabelButton::label() const {
  return label_;
}

gfx::Rect LabelButton::GetChildAreaBounds() {
  return GetLocalBounds();
}

bool LabelButton::ShouldUseFloodFillInkDrop() const {
  return !GetText().empty();
}

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

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

void LabelButton::OnNativeThemeChanged(const ui::NativeTheme* theme) {
  ResetColorsFromNativeTheme();
  UpdateThemedBorder();
  ResetLabelEnabledColor();
  // Invalidate the layout to pickup the new insets from the border.
  InvalidateLayout();
  // The entire button has to be repainted here, since the native theme can
  // define the tint for the entire background/border/focus ring.
  SchedulePaint();
}

void LabelButton::AddInkDropLayer(ui::Layer* ink_drop_layer) {
  image()->SetPaintToLayer();
  image()->layer()->SetFillsBoundsOpaquely(false);
  ink_drop_container_->AddInkDropLayer(ink_drop_layer);
  InstallInkDropMask(ink_drop_layer);
}

void LabelButton::RemoveInkDropLayer(ui::Layer* ink_drop_layer) {
  image()->DestroyLayer();
  ResetInkDropMask();
  ink_drop_container_->RemoveInkDropLayer(ink_drop_layer);
}

std::unique_ptr<InkDrop> LabelButton::CreateInkDrop() {
  return ShouldUseFloodFillInkDrop() ? CreateDefaultFloodFillInkDropImpl()
                                     : Button::CreateInkDrop();
}

std::unique_ptr<views::InkDropRipple> LabelButton::CreateInkDropRipple() const {
  return ShouldUseFloodFillInkDrop()
             ? std::make_unique<views::FloodFillInkDropRipple>(
                   size(), GetInkDropCenterBasedOnLastEvent(),
                   GetInkDropBaseColor(), ink_drop_visible_opacity())
             : CreateDefaultInkDropRipple(
                   image()->GetMirroredBounds().CenterPoint());
}

std::unique_ptr<views::InkDropHighlight> LabelButton::CreateInkDropHighlight()
    const {
  return ShouldUseFloodFillInkDrop()
             ? std::make_unique<views::InkDropHighlight>(
                   size(), ink_drop_small_corner_radius(),
                   gfx::RectF(GetLocalBounds()).CenterPoint(),
                   GetInkDropBaseColor())
             : CreateDefaultInkDropHighlight(
                   gfx::RectF(image()->GetMirroredBounds()).CenterPoint());
}

void LabelButton::StateChanged(ButtonState old_state) {
  const gfx::Size previous_image_size(image_->GetPreferredSize());
  UpdateImage();
  ResetLabelEnabledColor();
  label_->SetEnabled(state() != STATE_DISABLED);
  if (image_->GetPreferredSize() != previous_image_size)
    Layout();
}

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();
  bool button_style = style() == STYLE_BUTTON;
  // Button colors are used only for STYLE_BUTTON, otherwise we use label
  // colors. As it turns out, these are almost always the same color anyway in
  // pre-MD, although in the MD world labels and buttons get different colors.
  // TODO(estade): simplify this by removing STYLE_BUTTON.
  SkColor colors[STATE_COUNT] = {
      theme->GetSystemColor(button_style
                                ? ui::NativeTheme::kColorId_ButtonEnabledColor
                                : ui::NativeTheme::kColorId_LabelEnabledColor),
      theme->GetSystemColor(button_style
                                ? ui::NativeTheme::kColorId_ButtonHoverColor
                                : ui::NativeTheme::kColorId_LabelEnabledColor),
      theme->GetSystemColor(button_style
                                ? ui::NativeTheme::kColorId_ButtonHoverColor
                                : ui::NativeTheme::kColorId_LabelEnabledColor),
      theme->GetSystemColor(button_style
                                ? ui::NativeTheme::kColorId_ButtonDisabledColor
                                : ui::NativeTheme::kColorId_LabelDisabledColor),
  };

  // Use hardcoded colors for inverted color scheme support and STYLE_BUTTON.
  if (color_utils::IsInvertedColorScheme()) {
    colors[STATE_NORMAL] = colors[STATE_HOVERED] = colors[STATE_PRESSED] =
        SK_ColorWHITE;
    label_->SetBackgroundColor(SK_ColorBLACK);
    label_->SetBackground(CreateSolidBackground(SK_ColorBLACK));
    label_->SetAutoColorReadabilityEnabled(true);
    label_->SetShadows(gfx::ShadowValues());
  } else {
    if (style() == STYLE_BUTTON)
      PlatformStyle::ApplyLabelButtonTextStyle(label_, &colors);
    label_->SetBackground(nullptr);
    label_->SetAutoColorReadabilityEnabled(false);
  }

  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::UpdateStyleToIndicateDefaultStatus() {
  // Check that a subclass hasn't replaced the Label font. These buttons may
  // never be given default status.
  DCHECK_EQ(cached_normal_font_list_.GetFontSize(),
            label()->font_list().GetFontSize());
  // TODO(tapted): This should use style::GetFont(), but this part can just be
  // deleted when default buttons no longer go bold. Colors will need updating
  // still.
  label_->SetFontList(is_default_ ? cached_default_button_font_list_
                                  : cached_normal_font_list_);
  InvalidateLayout();
  ResetLabelEnabledColor();
}

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

void LabelButton::UpdateThemedBorder() {
  // Don't override borders set by others.
  if (!border_is_themed_border_)
    return;

  SetBorder(PlatformStyle::CreateThemedLabelButtonBorder(this));
  border_is_themed_border_ = true;
}

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

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

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();
}

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;
}

void LabelButton::ResetCachedPreferredSize() {
  cached_preferred_size_valid_ = false;
  cached_preferred_size_ = gfx::Size();
}

gfx::Size LabelButton::GetUnclampedSizeWithoutLabel() const {
  const gfx::Size image_size = image_->GetPreferredSize();
  gfx::Size size = image_size;
  const gfx::Insets insets(GetInsets());
  size.Enlarge(insets.width(), insets.height());

  // Accommodate for spacing between image and text if both are present.
  if (!GetText().empty() && image_size.width() > 0)
    size.Enlarge(image_label_spacing_, 0);

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

  return size;
}

void LabelButton::ResetLabelEnabledColor() {
  const SkColor color = button_state_colors_[state()];
  if (state() != STATE_DISABLED && label_->enabled_color() != color)
    label_->SetEnabledColor(color);
}

}  // namespace views