ui/views/examples/layout_example_base.cc - chromium/src - Git at Google

 // Copyright 2018 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/examples/layout_example_base.h"

 #include <algorithm>
 #include <memory>

 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/button/checkbox.h"
 #include "ui/views/controls/button/md_text_button.h"
 #include "ui/views/controls/combobox/combobox.h"
 #include "ui/views/controls/textfield/textfield.h"
 #include "ui/views/examples/example_combobox_model.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/view_class_properties.h"

 namespace views {
 namespace examples {

 namespace {

 constexpr int kLayoutExampleVerticalSpacing = 3;
 constexpr int kLayoutExampleLeftPadding = 8;
 constexpr gfx::Size kLayoutExampleDefaultChildSize(180, 90);

 // This View holds two other views which consists of a view on the left onto
 // which the BoxLayout is attached for demonstrating its features. The view
 // on the right contains all the various controls which allow the user to
 // interactively control the various features/properties of BoxLayout. Layout()
 // will ensure the left view takes 75% and the right view fills the remaining
 // 25%.
 class FullPanel : public View {
  public:
   FullPanel() = default;
   ~FullPanel() override = default;

  private:
   DISALLOW_COPY_AND_ASSIGN(FullPanel);
 };

 }  // namespace

 LayoutExampleBase::ChildPanel::ChildPanel(LayoutExampleBase* example)
     : example_(example) {
   SetBorder(CreateSolidBorder(1, SK_ColorGRAY));
   margin_.left = CreateTextfield();
   margin_.top = CreateTextfield();
   margin_.right = CreateTextfield();
   margin_.bottom = CreateTextfield();
   flex_ = CreateTextfield();
   flex_->SetText(base::ASCIIToUTF16(""));
 }

 LayoutExampleBase::ChildPanel::~ChildPanel() = default;

 bool LayoutExampleBase::ChildPanel::OnMousePressed(
     const ui::MouseEvent& event) {
   if (event.IsOnlyLeftMouseButton())
     SetSelected(true);
   return true;
 }

 void LayoutExampleBase::ChildPanel::Layout() {
   const int kSpacing = 2;
   if (selected_) {
     gfx::Rect client = GetContentsBounds();
     margin_.top->SetPosition(
         gfx::Point((client.width() - margin_.top->width()) / 2, kSpacing));
     margin_.left->SetPosition(
         gfx::Point(kSpacing, (client.height() - margin_.left->height()) / 2));
     margin_.bottom->SetPosition(
         gfx::Point((client.width() - margin_.bottom->width()) / 2,
                    client.height() - margin_.bottom->height() - kSpacing));
     margin_.right->SetPosition(
         gfx::Point(client.width() - margin_.right->width() - kSpacing,
                    (client.height() - margin_.right->height()) / 2));
     flex_->SetPosition(gfx::Point((client.width() - flex_->width()) / 2,
                                   (client.height() - flex_->height()) / 2));
   }
 }

 void LayoutExampleBase::ChildPanel::SetSelected(bool value) {
   if (value != selected_) {
     selected_ = value;
     SetBorder(CreateSolidBorder(1, selected_ ? SK_ColorBLACK : SK_ColorGRAY));
     if (selected_ && parent()) {
       for (View* child : parent()->children()) {
         if (child != this && child->GetGroup() == GetGroup())
           static_cast<ChildPanel*>(child)->SetSelected(false);
       }
     }
     margin_.left->SetVisible(selected_);
     margin_.top->SetVisible(selected_);
     margin_.right->SetVisible(selected_);
     margin_.bottom->SetVisible(selected_);
     flex_->SetVisible(selected_);
     InvalidateLayout();
     example_->RefreshLayoutPanel(false);
   }
 }

 int LayoutExampleBase::ChildPanel::GetFlex() {
   int flex;
   if (base::StringToInt(flex_->GetText(), &flex))
     return flex;
   return -1;
 }

 void LayoutExampleBase::ChildPanel::ContentsChanged(
     Textfield* sender,
     const base::string16& new_contents) {
   const gfx::Insets margins = LayoutExampleBase::TextfieldsToInsets(margin_);
   if (!margins.IsEmpty())
     this->SetProperty(kMarginsKey, margins);
   else
     this->ClearProperty(kMarginsKey);
   example_->RefreshLayoutPanel(sender == flex_);
 }

 Textfield* LayoutExampleBase::ChildPanel::CreateTextfield() {
   Textfield* textfield = new Textfield();
   textfield->SetDefaultWidthInChars(3);
   textfield->SizeToPreferredSize();
   textfield->SetText(base::ASCIIToUTF16("0"));
   textfield->set_controller(this);
   textfield->SetVisible(false);
   AddChildView(textfield);
   return textfield;
 }

 LayoutExampleBase::LayoutExampleBase(const char* title) : ExampleBase(title) {}

 LayoutExampleBase::~LayoutExampleBase() = default;

 Combobox* LayoutExampleBase::CreateCombobox(const base::string16& label_text,
                                             const char* const* items,
                                             int count,
                                             int* vertical_pos) {
   Label* label = new Label(label_text);
   label->SetPosition(gfx::Point(kLayoutExampleLeftPadding, *vertical_pos));
   label->SizeToPreferredSize();
   Combobox* combo_box =
       new Combobox(std::make_unique<ExampleComboboxModel>(items, count));
   combo_box->SetPosition(
       gfx::Point(label->x() + label->width() + kLayoutExampleVerticalSpacing,
                  *vertical_pos));
   combo_box->SizeToPreferredSize();
   combo_box->set_listener(this);
   label->SetSize(gfx::Size(label->width(), combo_box->height()));
   control_panel_->AddChildView(label);
   control_panel_->AddChildView(combo_box);
   *vertical_pos += combo_box->height() + kLayoutExampleVerticalSpacing;
   return combo_box;
 }

 Textfield* LayoutExampleBase::CreateRawTextfield(int vertical_pos,
                                                  bool add,
                                                  int* horizontal_pos) {
   Textfield* text_field = new Textfield();
   text_field->SetPosition(gfx::Point(*horizontal_pos, vertical_pos));
   text_field->SetDefaultWidthInChars(3);
   text_field->SetTextInputType(ui::TEXT_INPUT_TYPE_NUMBER);
   text_field->SizeToPreferredSize();
   text_field->SetText(base::ASCIIToUTF16("0"));
   text_field->set_controller(this);
   *horizontal_pos += text_field->width() + kLayoutExampleVerticalSpacing;
   if (add)
     control_panel_->AddChildView(text_field);
   return text_field;
 }

 Textfield* LayoutExampleBase::CreateTextfield(const base::string16& label_text,
                                               int* vertical_pos) {
   Label* label = new Label(label_text);
   label->SetPosition(gfx::Point(kLayoutExampleLeftPadding, *vertical_pos));
   label->SizeToPreferredSize();
   int horizontal_pos =
       label->x() + label->width() + kLayoutExampleVerticalSpacing;
   Textfield* text_field =
       CreateRawTextfield(*vertical_pos, false, &horizontal_pos);
   label->SetSize(gfx::Size(label->width(), text_field->height()));
   control_panel_->AddChildView(label);
   control_panel_->AddChildView(text_field);
   *vertical_pos += text_field->height() + kLayoutExampleVerticalSpacing;
   return text_field;
 }

 void LayoutExampleBase::CreateMarginsTextFields(
     const base::string16& label_text,
     Textfield* textfields[4],
     int* vertical_pos) {
   textfields[0] = CreateTextfield(label_text, vertical_pos);
   int center = textfields[0]->x() + textfields[0]->width() / 2;
   int horizontal_pos = std::max(
       0, center - (textfields[0]->width() + kLayoutExampleVerticalSpacing / 2));
   textfields[1] = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
   textfields[3] = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
   *vertical_pos = textfields[1]->y() + textfields[1]->height() +
                   kLayoutExampleVerticalSpacing;
   horizontal_pos = textfields[0]->x();
   textfields[2] = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
   *vertical_pos = textfields[2]->y() + textfields[2]->height() +
                   kLayoutExampleVerticalSpacing;
 }

 void LayoutExampleBase::CreateMarginsTextFields(
     const base::string16& label_text,
     InsetTextfields* textfields,
     int* vertical_pos) {
   textfields->top = CreateTextfield(label_text, vertical_pos);
   int center = textfields->top->x() + textfields->top->width() / 2;
   int horizontal_pos = std::max(
       0,
       center - (textfields->top->width() + kLayoutExampleVerticalSpacing / 2));
   textfields->left = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
   textfields->right = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
   *vertical_pos = textfields->left->y() + textfields->left->height() +
                   kLayoutExampleVerticalSpacing;
   horizontal_pos = textfields->top->x();
   textfields->bottom = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
   *vertical_pos = textfields->bottom->y() + textfields->bottom->height() +
                   kLayoutExampleVerticalSpacing;
 }

 Checkbox* LayoutExampleBase::CreateCheckbox(const base::string16& label_text,
                                             int* vertical_pos) {
   Checkbox* checkbox = new Checkbox(label_text, this);
   checkbox->SetPosition(gfx::Point(kLayoutExampleLeftPadding, *vertical_pos));
   checkbox->SizeToPreferredSize();
   control_panel_->AddChildView(checkbox);
   *vertical_pos += checkbox->height() + kLayoutExampleVerticalSpacing;
   return checkbox;
 }

 void LayoutExampleBase::CreateExampleView(View* container) {
   container->SetLayoutManager(std::make_unique<FillLayout>());
   View* full_panel = new FullPanel();
   container->AddChildView(full_panel);

   auto* manager = full_panel->SetLayoutManager(
       std::make_unique<BoxLayout>(views::BoxLayout::Orientation::kHorizontal));
   layout_panel_ = new View();
   layout_panel_->SetBorder(CreateSolidBorder(1, SK_ColorLTGRAY));
   full_panel->AddChildView(layout_panel_);
   manager->SetFlexForView(layout_panel_, 3);
   control_panel_ = new View();
   full_panel->AddChildView(control_panel_);
   manager->SetFlexForView(control_panel_, 1);

   int vertical_pos = kLayoutExampleVerticalSpacing;
   int horizontal_pos = kLayoutExampleLeftPadding;
   auto add_button =
       MdTextButton::CreateSecondaryUiButton(this, base::ASCIIToUTF16("Add"));
   add_button->SetPosition(gfx::Point(horizontal_pos, vertical_pos));
   add_button->SizeToPreferredSize();
   add_button_ = control_panel_->AddChildView(std::move(add_button));
   horizontal_pos += add_button_->width() + kLayoutExampleVerticalSpacing;

   preferred_width_view_ =
       CreateRawTextfield(vertical_pos, true, &horizontal_pos);
   preferred_width_view_->SetY(
       vertical_pos +
       (add_button_->height() - preferred_width_view_->height()) / 2);
   preferred_width_view_->SetText(
       base::NumberToString16(kLayoutExampleDefaultChildSize.width()));

   preferred_height_view_ =
       CreateRawTextfield(vertical_pos, true, &horizontal_pos);
   preferred_height_view_->SetY(
       vertical_pos +
       (add_button_->height() - preferred_height_view_->height()) / 2);
   preferred_height_view_->SetText(
       base::NumberToString16(kLayoutExampleDefaultChildSize.height()));

   CreateAdditionalControls(add_button_->y() + add_button_->height() +
                            kLayoutExampleVerticalSpacing);
 }

 void LayoutExampleBase::ButtonPressed(Button* sender, const ui::Event& event) {
   constexpr int kChildPanelGroup = 100;

   if (sender == add_button_) {
     std::unique_ptr<ChildPanel> panel = std::make_unique<ChildPanel>(this);
     panel->SetPreferredSize(GetNewChildPanelPreferredSize());
     panel->SetGroup(kChildPanelGroup);
     layout_panel_->AddChildView(std::move(panel));
     RefreshLayoutPanel(false);
   } else {
     ButtonPressedImpl(sender);
   }
 }

 // Default implementation is to do nothing.
 void LayoutExampleBase::ButtonPressedImpl(Button* sender) {}

 void LayoutExampleBase::RefreshLayoutPanel(bool update_layout) {
   if (update_layout)
     UpdateLayoutManager();
   layout_panel_->InvalidateLayout();
   layout_panel_->SchedulePaint();
 }

 gfx::Size LayoutExampleBase::GetNewChildPanelPreferredSize() {
   int width;
   if (!base::StringToInt(preferred_width_view_->GetText(), &width))
     width = kLayoutExampleDefaultChildSize.width();

   int height;
   if (!base::StringToInt(preferred_height_view_->GetText(), &height))
     height = kLayoutExampleDefaultChildSize.height();

   return gfx::Size(std::max(0, width), std::max(0, height));
 }

 gfx::Insets LayoutExampleBase::TextfieldsToInsets(
     const InsetTextfields& textfields,
     const gfx::Insets& default_insets) {
   int top;
   int left;
   int bottom;
   int right;
   if (!base::StringToInt(textfields.top->GetText(), &top))
     top = default_insets.top();
   if (!base::StringToInt(textfields.left->GetText(), &left))
     left = default_insets.left();
   if (!base::StringToInt(textfields.bottom->GetText(), &bottom))
     bottom = default_insets.bottom();
   if (!base::StringToInt(textfields.right->GetText(), &right))
     right = default_insets.right();

   return gfx::Insets(std::max(0, top), std::max(0, left), std::max(0, bottom),
                      std::max(0, right));
 }

 }  // namespace examples
 }  // namespace views
	// Copyright 2018 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/examples/layout_example_base.h"

	#include <algorithm>
	#include <memory>

	#include "base/strings/string16.h"
	#include "base/strings/string_number_conversions.h"
	#include "base/strings/utf_string_conversions.h"
	#include "ui/views/border.h"
	#include "ui/views/controls/button/checkbox.h"
	#include "ui/views/controls/button/md_text_button.h"
	#include "ui/views/controls/combobox/combobox.h"
	#include "ui/views/controls/textfield/textfield.h"
	#include "ui/views/examples/example_combobox_model.h"
	#include "ui/views/layout/box_layout.h"
	#include "ui/views/layout/fill_layout.h"
	#include "ui/views/view_class_properties.h"

	namespace views {
	namespace examples {

	namespace {

	constexpr int kLayoutExampleVerticalSpacing = 3;
	constexpr int kLayoutExampleLeftPadding = 8;
	constexpr gfx::Size kLayoutExampleDefaultChildSize(180, 90);

	// This View holds two other views which consists of a view on the left onto
	// which the BoxLayout is attached for demonstrating its features. The view
	// on the right contains all the various controls which allow the user to
	// interactively control the various features/properties of BoxLayout. Layout()
	// will ensure the left view takes 75% and the right view fills the remaining
	// 25%.
	class FullPanel : public View {
	public:
	FullPanel() = default;
	~FullPanel() override = default;

	private:
	DISALLOW_COPY_AND_ASSIGN(FullPanel);
	};

	} // namespace

	LayoutExampleBase::ChildPanel::ChildPanel(LayoutExampleBase* example)
	: example_(example) {
	SetBorder(CreateSolidBorder(1, SK_ColorGRAY));
	margin_.left = CreateTextfield();
	margin_.top = CreateTextfield();
	margin_.right = CreateTextfield();
	margin_.bottom = CreateTextfield();
	flex_ = CreateTextfield();
	flex_->SetText(base::ASCIIToUTF16(""));
	}

	LayoutExampleBase::ChildPanel::~ChildPanel() = default;

	bool LayoutExampleBase::ChildPanel::OnMousePressed(
	const ui::MouseEvent& event) {
	if (event.IsOnlyLeftMouseButton())
	SetSelected(true);
	return true;
	}

	void LayoutExampleBase::ChildPanel::Layout() {
	const int kSpacing = 2;
	if (selected_) {
	gfx::Rect client = GetContentsBounds();
	margin_.top->SetPosition(
	gfx::Point((client.width() - margin_.top->width()) / 2, kSpacing));
	margin_.left->SetPosition(
	gfx::Point(kSpacing, (client.height() - margin_.left->height()) / 2));
	margin_.bottom->SetPosition(
	gfx::Point((client.width() - margin_.bottom->width()) / 2,
	client.height() - margin_.bottom->height() - kSpacing));
	margin_.right->SetPosition(
	gfx::Point(client.width() - margin_.right->width() - kSpacing,
	(client.height() - margin_.right->height()) / 2));
	flex_->SetPosition(gfx::Point((client.width() - flex_->width()) / 2,
	(client.height() - flex_->height()) / 2));
	}
	}

	void LayoutExampleBase::ChildPanel::SetSelected(bool value) {
	if (value != selected_) {
	selected_ = value;
	SetBorder(CreateSolidBorder(1, selected_ ? SK_ColorBLACK : SK_ColorGRAY));
	if (selected_ && parent()) {
	for (View* child : parent()->children()) {
	if (child != this && child->GetGroup() == GetGroup())
	static_cast<ChildPanel*>(child)->SetSelected(false);
	}
	}
	margin_.left->SetVisible(selected_);
	margin_.top->SetVisible(selected_);
	margin_.right->SetVisible(selected_);
	margin_.bottom->SetVisible(selected_);
	flex_->SetVisible(selected_);
	InvalidateLayout();
	example_->RefreshLayoutPanel(false);
	}
	}

	int LayoutExampleBase::ChildPanel::GetFlex() {
	int flex;
	if (base::StringToInt(flex_->GetText(), &flex))
	return flex;
	return -1;
	}

	void LayoutExampleBase::ChildPanel::ContentsChanged(
	Textfield* sender,
	const base::string16& new_contents) {
	const gfx::Insets margins = LayoutExampleBase::TextfieldsToInsets(margin_);
	if (!margins.IsEmpty())
	this->SetProperty(kMarginsKey, margins);
	else
	this->ClearProperty(kMarginsKey);
	example_->RefreshLayoutPanel(sender == flex_);
	}

	Textfield* LayoutExampleBase::ChildPanel::CreateTextfield() {
	Textfield* textfield = new Textfield();
	textfield->SetDefaultWidthInChars(3);
	textfield->SizeToPreferredSize();
	textfield->SetText(base::ASCIIToUTF16("0"));
	textfield->set_controller(this);
	textfield->SetVisible(false);
	AddChildView(textfield);
	return textfield;
	}

	LayoutExampleBase::LayoutExampleBase(const char* title) : ExampleBase(title) {}

	LayoutExampleBase::~LayoutExampleBase() = default;

	Combobox* LayoutExampleBase::CreateCombobox(const base::string16& label_text,
	const char* const* items,
	int count,
	int* vertical_pos) {
	Label* label = new Label(label_text);
	label->SetPosition(gfx::Point(kLayoutExampleLeftPadding, *vertical_pos));
	label->SizeToPreferredSize();
	Combobox* combo_box =
	new Combobox(std::make_unique<ExampleComboboxModel>(items, count));
	combo_box->SetPosition(
	gfx::Point(label->x() + label->width() + kLayoutExampleVerticalSpacing,
	*vertical_pos));
	combo_box->SizeToPreferredSize();
	combo_box->set_listener(this);
	label->SetSize(gfx::Size(label->width(), combo_box->height()));
	control_panel_->AddChildView(label);
	control_panel_->AddChildView(combo_box);
	*vertical_pos += combo_box->height() + kLayoutExampleVerticalSpacing;
	return combo_box;
	}

	Textfield* LayoutExampleBase::CreateRawTextfield(int vertical_pos,
	bool add,
	int* horizontal_pos) {
	Textfield* text_field = new Textfield();
	text_field->SetPosition(gfx::Point(*horizontal_pos, vertical_pos));
	text_field->SetDefaultWidthInChars(3);
	text_field->SetTextInputType(ui::TEXT_INPUT_TYPE_NUMBER);
	text_field->SizeToPreferredSize();
	text_field->SetText(base::ASCIIToUTF16("0"));
	text_field->set_controller(this);
	*horizontal_pos += text_field->width() + kLayoutExampleVerticalSpacing;
	if (add)
	control_panel_->AddChildView(text_field);
	return text_field;
	}

	Textfield* LayoutExampleBase::CreateTextfield(const base::string16& label_text,
	int* vertical_pos) {
	Label* label = new Label(label_text);
	label->SetPosition(gfx::Point(kLayoutExampleLeftPadding, *vertical_pos));
	label->SizeToPreferredSize();
	int horizontal_pos =
	label->x() + label->width() + kLayoutExampleVerticalSpacing;
	Textfield* text_field =
	CreateRawTextfield(*vertical_pos, false, &horizontal_pos);
	label->SetSize(gfx::Size(label->width(), text_field->height()));
	control_panel_->AddChildView(label);
	control_panel_->AddChildView(text_field);
	*vertical_pos += text_field->height() + kLayoutExampleVerticalSpacing;
	return text_field;
	}

	void LayoutExampleBase::CreateMarginsTextFields(
	const base::string16& label_text,
	Textfield* textfields[4],
	int* vertical_pos) {
	textfields[0] = CreateTextfield(label_text, vertical_pos);
	int center = textfields[0]->x() + textfields[0]->width() / 2;
	int horizontal_pos = std::max(
	0, center - (textfields[0]->width() + kLayoutExampleVerticalSpacing / 2));
	textfields[1] = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
	textfields[3] = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
	*vertical_pos = textfields[1]->y() + textfields[1]->height() +
	kLayoutExampleVerticalSpacing;
	horizontal_pos = textfields[0]->x();
	textfields[2] = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
	*vertical_pos = textfields[2]->y() + textfields[2]->height() +
	kLayoutExampleVerticalSpacing;
	}

	void LayoutExampleBase::CreateMarginsTextFields(
	const base::string16& label_text,
	InsetTextfields* textfields,
	int* vertical_pos) {
	textfields->top = CreateTextfield(label_text, vertical_pos);
	int center = textfields->top->x() + textfields->top->width() / 2;
	int horizontal_pos = std::max(
	0,
	center - (textfields->top->width() + kLayoutExampleVerticalSpacing / 2));
	textfields->left = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
	textfields->right = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
	*vertical_pos = textfields->left->y() + textfields->left->height() +
	kLayoutExampleVerticalSpacing;
	horizontal_pos = textfields->top->x();
	textfields->bottom = CreateRawTextfield(*vertical_pos, true, &horizontal_pos);
	*vertical_pos = textfields->bottom->y() + textfields->bottom->height() +
	kLayoutExampleVerticalSpacing;
	}

	Checkbox* LayoutExampleBase::CreateCheckbox(const base::string16& label_text,
	int* vertical_pos) {
	Checkbox* checkbox = new Checkbox(label_text, this);
	checkbox->SetPosition(gfx::Point(kLayoutExampleLeftPadding, *vertical_pos));
	checkbox->SizeToPreferredSize();
	control_panel_->AddChildView(checkbox);
	*vertical_pos += checkbox->height() + kLayoutExampleVerticalSpacing;
	return checkbox;
	}

	void LayoutExampleBase::CreateExampleView(View* container) {
	container->SetLayoutManager(std::make_unique<FillLayout>());
	View* full_panel = new FullPanel();
	container->AddChildView(full_panel);

	auto* manager = full_panel->SetLayoutManager(
	std::make_unique<BoxLayout>(views::BoxLayout::Orientation::kHorizontal));
	layout_panel_ = new View();
	layout_panel_->SetBorder(CreateSolidBorder(1, SK_ColorLTGRAY));
	full_panel->AddChildView(layout_panel_);
	manager->SetFlexForView(layout_panel_, 3);
	control_panel_ = new View();
	full_panel->AddChildView(control_panel_);
	manager->SetFlexForView(control_panel_, 1);

	int vertical_pos = kLayoutExampleVerticalSpacing;
	int horizontal_pos = kLayoutExampleLeftPadding;
	auto add_button =
	MdTextButton::CreateSecondaryUiButton(this, base::ASCIIToUTF16("Add"));
	add_button->SetPosition(gfx::Point(horizontal_pos, vertical_pos));
	add_button->SizeToPreferredSize();
	add_button_ = control_panel_->AddChildView(std::move(add_button));
	horizontal_pos += add_button_->width() + kLayoutExampleVerticalSpacing;

	preferred_width_view_ =
	CreateRawTextfield(vertical_pos, true, &horizontal_pos);
	preferred_width_view_->SetY(
	vertical_pos +
	(add_button_->height() - preferred_width_view_->height()) / 2);
	preferred_width_view_->SetText(
	base::NumberToString16(kLayoutExampleDefaultChildSize.width()));

	preferred_height_view_ =
	CreateRawTextfield(vertical_pos, true, &horizontal_pos);
	preferred_height_view_->SetY(
	vertical_pos +
	(add_button_->height() - preferred_height_view_->height()) / 2);
	preferred_height_view_->SetText(
	base::NumberToString16(kLayoutExampleDefaultChildSize.height()));

	CreateAdditionalControls(add_button_->y() + add_button_->height() +
	kLayoutExampleVerticalSpacing);
	}

	void LayoutExampleBase::ButtonPressed(Button* sender, const ui::Event& event) {
	constexpr int kChildPanelGroup = 100;

	if (sender == add_button_) {
	std::unique_ptr<ChildPanel> panel = std::make_unique<ChildPanel>(this);
	panel->SetPreferredSize(GetNewChildPanelPreferredSize());
	panel->SetGroup(kChildPanelGroup);
	layout_panel_->AddChildView(std::move(panel));
	RefreshLayoutPanel(false);
	} else {
	ButtonPressedImpl(sender);
	}
	}

	// Default implementation is to do nothing.
	void LayoutExampleBase::ButtonPressedImpl(Button* sender) {}

	void LayoutExampleBase::RefreshLayoutPanel(bool update_layout) {
	if (update_layout)
	UpdateLayoutManager();
	layout_panel_->InvalidateLayout();
	layout_panel_->SchedulePaint();
	}

	gfx::Size LayoutExampleBase::GetNewChildPanelPreferredSize() {
	int width;
	if (!base::StringToInt(preferred_width_view_->GetText(), &width))
	width = kLayoutExampleDefaultChildSize.width();

	int height;
	if (!base::StringToInt(preferred_height_view_->GetText(), &height))
	height = kLayoutExampleDefaultChildSize.height();

	return gfx::Size(std::max(0, width), std::max(0, height));
	}

	gfx::Insets LayoutExampleBase::TextfieldsToInsets(
	const InsetTextfields& textfields,
	const gfx::Insets& default_insets) {
	int top;
	int left;
	int bottom;
	int right;
	if (!base::StringToInt(textfields.top->GetText(), &top))
	top = default_insets.top();
	if (!base::StringToInt(textfields.left->GetText(), &left))
	left = default_insets.left();
	if (!base::StringToInt(textfields.bottom->GetText(), &bottom))
	bottom = default_insets.bottom();
	if (!base::StringToInt(textfields.right->GetText(), &right))
	right = default_insets.right();

	return gfx::Insets(std::max(0, top), std::max(0, left), std::max(0, bottom),
	std::max(0, right));
	}

	} // namespace examples
	} // namespace views