Demo: Tweak window option and style display

imgui_demo.cpp

@@ -139,7 +139,7 @@ void ImGui::ShowTestWindow(bool* p_opened)
     static bool no_scrollbar = false;
     static bool no_collapse = false;
     static bool no_menu = false;
-    static float bg_alpha = 0.65f;
+    static float bg_alpha = -0.01f; // <0: default
 
     // Demonstrate the various window flags. Typically you would just use the default.
     ImGuiWindowFlags window_flags = 0;
@@ -203,14 +203,17 @@ void ImGui::ShowTestWindow(bool* p_opened)
 
     if (ImGui::CollapsingHeader("Window options"))
     {
-        ImGui::Checkbox("no titlebar", &no_titlebar); ImGui::SameLine(150);
+        ImGui::Checkbox("No titlebar", &no_titlebar); ImGui::SameLine(150);
-        ImGui::Checkbox("no border", &no_border); ImGui::SameLine(300);
+        ImGui::Checkbox("No border", &no_border); ImGui::SameLine(300);
-        ImGui::Checkbox("no resize", &no_resize);
+        ImGui::Checkbox("No resize", &no_resize);
-        ImGui::Checkbox("no move", &no_move); ImGui::SameLine(150);
+        ImGui::Checkbox("No move", &no_move); ImGui::SameLine(150);
-        ImGui::Checkbox("no scrollbar", &no_scrollbar); ImGui::SameLine(300);
+        ImGui::Checkbox("No scrollbar", &no_scrollbar); ImGui::SameLine(300);
-        ImGui::Checkbox("no collapse", &no_collapse);
+        ImGui::Checkbox("No collapse", &no_collapse);
-        ImGui::Checkbox("no menu", &no_menu);
+        ImGui::Checkbox("No menu", &no_menu);
-        ImGui::SliderFloat("bg alpha", &bg_alpha, 0.0f, 1.0f);
+
+        ImGui::PushItemWidth(100);
+        ImGui::DragFloat("Window Fill Alpha", &bg_alpha, 0.005f, -0.01f, 1.0f, bg_alpha < 0.0f ? "(default)" : "%.3f"); // Not exposing zero here so user doesn't "lose" the UI (zero alpha clips all widgets). But application code could have a toggle to switch between zero and non-zero.
+        ImGui::PopItemWidth();
 
         if (ImGui::TreeNode("Style"))
         {
@@ -1509,16 +1512,16 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
         ImGui::PushItemWidth(100);
         ImGui::DragFloat("Curve Tessellation Tolerance", &style.CurveTessellationTol, 0.02f, 0.10f, FLT_MAX, NULL, 2.0f);
         if (style.CurveTessellationTol < 0.0f) style.CurveTessellationTol = 0.10f;
+        ImGui::DragFloat("Global Alpha", &style.Alpha, 0.005f, 0.20f, 1.0f, "%.2f"); // Not exposing zero here so user doesn't "lose" the UI (zero alpha clips all widgets). But application code could have a toggle to switch between zero and non-zero.
+        ImGui::DragFloat("Window Fill Alpha Default", &style.WindowFillAlphaDefault, 0.005f, 0.0f, 1.0f, "%.2f");
         ImGui::PopItemWidth();
         ImGui::TreePop();
     }
 
     if (ImGui::TreeNode("Sizes"))
     {
-        ImGui::SliderFloat("Alpha", &style.Alpha, 0.20f, 1.0f, "%.2f");                 // Not exposing zero here so user doesn't "lose" the UI. But application code could have a toggle to switch between zero and non-zero.
         ImGui::SliderFloat2("WindowPadding", (float*)&style.WindowPadding, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 16.0f, "%.0f");
-        ImGui::SliderFloat("WindowFillAlphaDefault", &style.WindowFillAlphaDefault, 0.0f, 1.0f, "%.2f");
         ImGui::SliderFloat("ChildWindowRounding", &style.ChildWindowRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat2("FramePadding", (float*)&style.FramePadding, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 16.0f, "%.0f");