＜2021SC@SDUSC＞【Overload游戏引擎】OvUI源码模块分析（六）——Widgets

• Button

namespace OvUI::Widgets::Buttons
{
	class AButton : public AWidget
	{
	protected:
		void _Draw_Impl() override = 0;

	public:
		OvTools::Eventing::Event<> ClickedEvent;
	};
}

定义按钮小部件的基类

OvUI::Widgets::Buttons::Button::Button(const std::string& p_label, const OvMaths::FVector2& p_size, bool p_disabled) :
	label(p_label), size(p_size), disabled(p_disabled)
{
	auto& style = ImGui::GetStyle();

	idleBackgroundColor		= Internal::Converter::ToColor(style.Colors[ImGuiCol_Button]);
	hoveredBackgroundColor	= Internal::Converter::ToColor(style.Colors[ImGuiCol_ButtonHovered]);
	clickedBackgroundColor	= Internal::Converter::ToColor(style.Colors[ImGuiCol_ButtonActive]);
	textColor				= Internal::Converter::ToColor(style.Colors[ImGuiCol_Text]);
}

void OvUI::Widgets::Buttons::Button::_Draw_Impl()
{
	auto& style = ImGui::GetStyle();

	auto defaultIdleColor		= style.Colors[ImGuiCol_Button];
	auto defaultHoveredColor	= style.Colors[ImGuiCol_ButtonHovered];
	auto defaultClickedColor	= style.Colors[ImGuiCol_ButtonActive];
	auto defaultTextColor		= style.Colors[ImGuiCol_Text];

	style.Colors[ImGuiCol_Button]			= OvUI::Internal::Converter::ToImVec4(idleBackgroundColor);
	style.Colors[ImGuiCol_ButtonHovered]	= OvUI::Internal::Converter::ToImVec4(hoveredBackgroundColor);
	style.Colors[ImGuiCol_ButtonActive]		= OvUI::Internal::Converter::ToImVec4(clickedBackgroundColor);
	style.Colors[ImGuiCol_Text]				= OvUI::Internal::Converter::ToImVec4(textColor);

	if (ImGui::ButtonEx((label + m_widgetID).c_str(), Internal::Converter::ToImVec2(size), disabled ? ImGuiButtonFlags_Disabled : 0))
		ClickedEvent.Invoke();

	style.Colors[ImGuiCol_Button]			= defaultIdleColor;
	style.Colors[ImGuiCol_ButtonHovered]	= defaultHoveredColor;
	style.Colors[ImGuiCol_ButtonActive]		= defaultClickedColor;
	style.Colors[ImGuiCol_Text]				= defaultTextColor;
}

这是一个简单按钮小部件的实现。

OvUI::Widgets::Buttons::ButtonArrow::ButtonArrow(ImGuiDir p_direction) :
	direction(p_direction)
{
}

void OvUI::Widgets::Buttons::ButtonArrow::_Draw_Impl()
{
	if (ImGui::ArrowButton(m_widgetID.c_str(), direction))
		ClickedEvent.Invoke();
}

带有箭头的按钮小部件的实现，需要使用ImGui库中的箭头按钮。

OvUI::Widgets::Buttons::ButtonColored::ButtonColored(const std::string & p_label, const Types::Color& p_color, const OvMaths::FVector2& p_size, bool p_enableAlpha) :
	label(p_label), color(p_color), size(p_size), enableAlpha(p_enableAlpha)
{
}

void OvUI::Widgets::Buttons::ButtonColored::_Draw_Impl()
{
	ImVec4 imColor = Internal::Converter::ToImVec4(color);

	if (ImGui::ColorButton((label + m_widgetID).c_str(), imColor, !enableAlpha ? ImGuiColorEditFlags_NoAlpha : 0, Internal::Converter::ToImVec2(size)))
		ClickedEvent.Invoke();

	color = Internal::Converter::ToColor(imColor);
}

这是一个单一颜色的按钮小部件的实现，需要使用调色板元素。

OvUI::Widgets::Buttons::ButtonImage::ButtonImage(uint32_t p_textureID, const OvMaths::FVector2 & p_size) :
	textureID{ p_textureID }, size(p_size)
{
}

void OvUI::Widgets::Buttons::ButtonImage::_Draw_Impl()
{
	ImVec4 bg = Internal::Converter::ToImVec4(background);
	ImVec4 tn = Internal::Converter::ToImVec4(tint);

	if (ImGui::ImageButton(textureID.raw, Internal::Converter::ToImVec2(size), ImVec2(0.f, 1.f), ImVec2(1.f, 0.f), -1, bg, tn, disabled ? ImGuiButtonFlags_Disabled : 0))
		ClickedEvent.Invoke();
}

带有图像的按钮小部件

OvUI::Widgets::Buttons::ButtonSmall::ButtonSmall(const std::string& p_label) :
	label(p_label)
{
	auto& style = ImGui::GetStyle();

	idleBackgroundColor = Internal::Converter::ToColor(style.Colors[ImGuiCol_Button]);
	hoveredBackgroundColor = Internal::Converter::ToColor(style.Colors[ImGuiCol_ButtonHovered]);
	clickedBackgroundColor = Internal::Converter::ToColor(style.Colors[ImGuiCol_ButtonActive]);
	textColor = Internal::Converter::ToColor(style.Colors[ImGuiCol_Text]);
}

void OvUI::Widgets::Buttons::ButtonSmall::_Draw_Impl()
{
	auto& style = ImGui::GetStyle();

	auto defaultIdleColor		= style.Colors[ImGuiCol_Button];
	auto defaultHoveredColor	= style.Colors[ImGuiCol_ButtonHovered];
	auto defaultClickedColor	= style.Colors[ImGuiCol_ButtonActive];
	auto defaultTextColor		= style.Colors[ImGuiCol_Text];

	style.Colors[ImGuiCol_Button]			= OvUI::Internal::Converter::ToImVec4(idleBackgroundColor);
	style.Colors[ImGuiCol_ButtonHovered]	= OvUI::Internal::Converter::ToImVec4(hoveredBackgroundColor);
	style.Colors[ImGuiCol_ButtonActive]		= OvUI::Internal::Converter::ToImVec4(clickedBackgroundColor);
	style.Colors[ImGuiCol_Text]				= OvUI::Internal::Converter::ToImVec4(textColor);

	if (ImGui::SmallButton((label + m_widgetID).c_str()))
		ClickedEvent.Invoke();

	style.Colors[ImGuiCol_Button]			= defaultIdleColor;
	style.Colors[ImGuiCol_ButtonHovered]	= defaultHoveredColor;
	style.Colors[ImGuiCol_ButtonActive]		= defaultClickedColor;
	style.Colors[ImGuiCol_Text]				= defaultTextColor;
}

小按钮小部件