ColorButton: Added ImGuiColorEditFlags_NoBorder flag to remove the border normally enforced by default.

docs/CHANGELOG.txt

@@ -36,6 +36,8 @@ HOW TO UPDATE?
 
 Other Changes:
 
+- ColorButton: Added ImGuiColorEditFlags_NoBorder flag to remove the border normally enforced
+  by default for standalone ColorButton.
 - Backends: Added SDL2+Metal example application. (#3017) [@coding-jackalope]
 
 

imgui.h

@@ -60,7 +60,7 @@ Index of this file:
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.75"
-#define IMGUI_VERSION_NUM           17500
+#define IMGUI_VERSION_NUM           17501
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 
 // Define attributes of all API symbols declarations (e.g. for DLL under Windows)
@@ -1158,6 +1158,7 @@ enum ImGuiColorEditFlags_
     ImGuiColorEditFlags_NoLabel         = 1 << 7,   //              // ColorEdit, ColorPicker: disable display of inline text label (the label is still forwarded to the tooltip and picker).
     ImGuiColorEditFlags_NoSidePreview   = 1 << 8,   //              // ColorPicker: disable bigger color preview on right side of the picker, use small colored square preview instead.
     ImGuiColorEditFlags_NoDragDrop      = 1 << 9,   //              // ColorEdit: disable drag and drop target. ColorButton: disable drag and drop source.
+    ImGuiColorEditFlags_NoBorder        = 1 << 10,  //              // ColorButton: disable border (which is enforced by default)
 
     // User Options (right-click on widget to change some of them).
     ImGuiColorEditFlags_AlphaBar        = 1 << 16,  //              // ColorEdit, ColorPicker: show vertical alpha bar/gradient in picker.

imgui_demo.cpp

@@ -1264,7 +1264,9 @@ static void ShowDemoWindowWidgets()
         }
 
         ImGui::Text("Color button only:");
-        ImGui::ColorButton("MyColor##3c", *(ImVec4*)&color, misc_flags, ImVec2(80,80));
+        static bool no_border = false;
+        ImGui::Checkbox("ImGuiColorEditFlags_NoBorder", &no_border);
+        ImGui::ColorButton("MyColor##3c", *(ImVec4*)&color, misc_flags | (no_border ? ImGuiColorEditFlags_NoBorder : 0), ImVec2(80,80));
 
         ImGui::Text("Color picker:");
         static bool alpha = true;

imgui_widgets.cpp

@@ -4956,8 +4956,12 @@ bool ImGui::ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFl
     float grid_step = ImMin(size.x, size.y) / 2.99f;
     float rounding = ImMin(g.Style.FrameRounding, grid_step * 0.5f);
     ImRect bb_inner = bb;
-    float off = -0.75f; // The border (using Col_FrameBg) tends to look off when color is near-opaque and rounding is enabled. This offset seemed like a good middle ground to reduce those artifacts.
-    bb_inner.Expand(off);
+    float off = 0.0f;
+    if ((flags & ImGuiColorEditFlags_NoBorder) == 0)
+    {
+        off = -0.75f; // The border (using Col_FrameBg) tends to look off when color is near-opaque and rounding is enabled. This offset seemed like a good middle ground to reduce those artifacts.
+        bb_inner.Expand(off);
+    }
     if ((flags & ImGuiColorEditFlags_AlphaPreviewHalf) && col_rgb.w < 1.0f)
     {
         float mid_x = IM_ROUND((bb_inner.Min.x + bb_inner.Max.x) * 0.5f);
@@ -4974,10 +4978,13 @@ bool ImGui::ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFl
             window->DrawList->AddRectFilled(bb_inner.Min, bb_inner.Max, GetColorU32(col_source), rounding, ImDrawCornerFlags_All);
     }
     RenderNavHighlight(bb, id);
-    if (g.Style.FrameBorderSize > 0.0f)
-        RenderFrameBorder(bb.Min, bb.Max, rounding);
-    else
-        window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), rounding); // Color button are often in need of some sort of border
+    if ((flags & ImGuiColorEditFlags_NoBorder) == 0)
+    {
+        if (g.Style.FrameBorderSize > 0.0f)
+            RenderFrameBorder(bb.Min, bb.Max, rounding);
+        else
+            window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), rounding); // Color button are often in need of some sort of border
+    }
 
     // Drag and Drop Source
     // NB: The ActiveId test is merely an optional micro-optimization, BeginDragDropSource() does the same test.