ColorButton: Added frame border when style border are off. (#346) @jdumas

imgui.cpp

@@ -152,8 +152,8 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
- - 2016/08/xx (1.XX) - removed ColorEditMode() and ImGuiColorEditMode in favor of ImGuiColorEditFlags and parameters to the various Color*() functions
-                     - changed prototype of 'ColorEdit4(const char* label, float col[4], bool show_alpha = true)' to 'ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flags = 0)', where passing flags = 0x01 is a safe no-op (hello dodgy backward compatibility!)
+ - 2017/07/30 (1.51) - removed ColorEditMode() and ImGuiColorEditMode in favor of ImGuiColorEditFlags and parameters to the various Color*() functions
+                     - changed prototype of 'ColorEdit4(const char* label, float col[4], bool show_alpha = true)' to 'ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flags = 0)', where passing flags = 0x01 is a safe no-op (hello dodgy backward compatibility!). - check and run the demo window, under "Color/Picker Widgets", to understand the various new options.
                      - changed prototype of rarely used 'ColorButton(ImVec4 col, bool small_height = false, bool outline_border = true)' to 'ColorButton(const char* desc_id, ImVec4 col, ImGuiColorEditFlags flags = 0, ImVec2 size = ImVec2(0,0))'
  - 2017/07/20 (1.51) - removed IsPosHoveringAnyWindow(ImVec2), which was partly broken and misleading. ASSERT + redirect user to io.WantCaptureMouse
  - 2017/05/26 (1.50) - removed ImFontConfig::MergeGlyphCenterV in favor of a more multipurpose ImFontConfig::GlyphOffset.
@@ -9115,7 +9115,10 @@ bool ImGui::ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFl
     {
         RenderColorRectWithAlphaCheckerboard(bb.Min, bb.Max, GetColorU32((flags & ImGuiColorEditFlags_AlphaPreview) ? col : col_without_alpha), grid_step, ImVec2(0,0), rounding);
     }
-    RenderFrameBorder(bb.Min, bb.Max, rounding);
+    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+        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 (hovered && !(flags & ImGuiColorEditFlags_NoTooltip))
         ColorTooltip(desc_id, &col.x, flags & (ImGuiColorEditFlags_NoAlpha | ImGuiColorEditFlags_AlphaPreview | ImGuiColorEditFlags_AlphaPreviewHalf));