Push/Pop TweakedTheme - Change theme per window

[colesnicov]

Hello. Could you implement ImGuiTheme::Push(ImGuiTweakedTheme ...)/ImGuiTheme::Pop methods for ImGuiTheme? I would like to be able to apply a theme to only one window, or to one element or group of elements..

[pthom]

Hello,

This is actually a good idea. I just added this feature.

See f5c6f82 (inside Hello ImGui)

And pthom/imgui_bundle@90298ce (inside ImGui Bundle)

[colesnicov]

I modified part of the code from imgui demo.cpp.
Specifically from the 'Style Editor':

static void Push(ImGuiStyle *_style_from) {
//	Main
	ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, _style_from->WindowPadding);
	ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, _style_from->FramePadding);
	ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, _style_from->ItemSpacing);
	ImGui::PushStyleVar(ImGuiStyleVar_ItemInnerSpacing, _style_from->ItemInnerSpacing);
	ImGui::PushStyleVar(ImGuiStyleVar_IndentSpacing, _style_from->IndentSpacing);
	ImGui::PushStyleVar(ImGuiStyleVar_ScrollbarSize, _style_from->ScrollbarSize);
	ImGui::PushStyleVar(ImGuiStyleVar_GrabMinSize, _style_from->GrabMinSize);
//	Borders
	ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, _style_from->WindowBorderSize);
	ImGui::PushStyleVar(ImGuiStyleVar_ChildBorderSize, _style_from->ChildBorderSize);
	ImGui::PushStyleVar(ImGuiStyleVar_PopupBorderSize, _style_from->PopupBorderSize);
	ImGui::PushStyleVar(ImGuiStyleVar_FrameBorderSize, _style_from->FrameBorderSize);
	ImGui::PushStyleVar(ImGuiStyleVar_TabBorderSize, _style_from->TabBorderSize);
	ImGui::PushStyleVar(ImGuiStyleVar_TabBarBorderSize, _style_from->TabBarBorderSize);
//	Rounding
	ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, _style_from->WindowRounding);
	ImGui::PushStyleVar(ImGuiStyleVar_ChildRounding, _style_from->ChildRounding);
	ImGui::PushStyleVar(ImGuiStyleVar_FrameRounding, _style_from->FrameRounding);
	ImGui::PushStyleVar(ImGuiStyleVar_PopupRounding, _style_from->PopupRounding);
	ImGui::PushStyleVar(ImGuiStyleVar_ScrollbarRounding, _style_from->ScrollbarRounding);
	ImGui::PushStyleVar(ImGuiStyleVar_GrabRounding, _style_from->GrabRounding);
	ImGui::PushStyleVar(ImGuiStyleVar_TabRounding, _style_from->TabRounding);
//	Tables
	ImGui::PushStyleVar(ImGuiStyleVar_CellPadding, _style_from->CellPadding);
	ImGui::PushStyleVar(ImGuiStyleVar_TableAngledHeadersAngle,
			_style_from->TableAngledHeadersAngle);
//	Widgets
	ImGui::PushStyleVar(ImGuiStyleVar_WindowTitleAlign, _style_from->WindowTitleAlign);
	ImGui::PushStyleVar(ImGuiStyleVar_ButtonTextAlign, _style_from->ButtonTextAlign);
	ImGui::PushStyleVar(ImGuiStyleVar_SelectableTextAlign, _style_from->SelectableTextAlign);
	ImGui::PushStyleVar(ImGuiStyleVar_SeparatorTextBorderSize,
			_style_from->SeparatorTextBorderSize);
	ImGui::PushStyleVar(ImGuiStyleVar_SeparatorTextAlign, _style_from->SeparatorTextAlign);
	ImGui::PushStyleVar(ImGuiStyleVar_SeparatorTextPadding, _style_from->SeparatorTextPadding);

//	Rendering
	ImGui::PushStyleVar(ImGuiStyleVar_Alpha, _style_from->Alpha);
	ImGui::PushStyleVar(ImGuiStyleVar_DisabledAlpha, _style_from->DisabledAlpha);

	//	Colors
	for (int i = 0; i < ImGuiCol_COUNT; i++) {
		ImGui::PushStyleColor(i, _style_from->Colors[i]);
	}
}

and

void Pop() {
	ImGui::PopStyleVar(ImGuiStyleVar_COUNT - 2);
	ImGui::PopStyleColor(ImGuiCol_COUNT);
}

Not all variables are set, some are global to the entire application. For example ImGuiStyleVar_TaouchExtraPadding and ImGuiStyleVar_AntiAliasedLines or Docking...