TreeNode: minor tidying up (#581, #324)

imgui.cpp

@@ -5671,7 +5671,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
         bb.Max.x += (float)(int)(window->WindowPadding.x*0.5f) - 1;
     }
 
-    const float collapser_width = g.FontSize + (display_frame ? padding.x*2 : padding.x);
+    const float text_offset_x = g.FontSize + (display_frame ? padding.x*3 : padding.x*2);             // Collapser arrow width + Spacing
     const float text_width = g.FontSize + (label_size.x > 0.0f ? label_size.x + padding.x*2 : 0.0f);   // Include collapser
     ItemSize(ImVec2(text_width, frame_height), text_base_offset_y);
 
@@ -5699,7 +5699,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
     {
         bool toggled = !(flags & (ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick));
         if (flags & ImGuiTreeNodeFlags_OpenOnArrow)
-            toggled |= IsMouseHoveringRect(interact_bb.Min, ImVec2(interact_bb.Min.x + collapser_width, interact_bb.Max.y));
+            toggled |= IsMouseHoveringRect(interact_bb.Min, ImVec2(interact_bb.Min.x + text_offset_x, interact_bb.Max.y));
         if (flags & ImGuiTreeNodeFlags_OpenOnDoubleClick)
             toggled |= g.IO.MouseDoubleClicked[0];
         if (toggled)
@@ -5713,7 +5713,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
 
     // Render
     const ImU32 col = GetColorU32((held && hovered) ? ImGuiCol_HeaderActive : hovered ? ImGuiCol_HeaderHovered : ImGuiCol_Header);
-    const ImVec2 text_pos = bb.Min + padding + ImVec2(collapser_width, text_base_offset_y);
+    const ImVec2 text_pos = bb.Min + ImVec2(text_offset_x, padding.y + text_base_offset_y);
     if (display_frame)
     {
         // Framed type
@@ -5740,7 +5740,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
             RenderFrame(bb.Min, bb.Max, col, false);
 
         if (flags & ImGuiTreeNodeFlags_AlwaysOpen)
-            RenderBullet(bb.Min + ImVec2((padding.x + collapser_width) * 0.5f, g.FontSize*0.50f + text_base_offset_y));
+            RenderBullet(bb.Min + ImVec2(text_offset_x * 0.5f, g.FontSize*0.50f + text_base_offset_y));
         else
             RenderCollapseTriangle(bb.Min + ImVec2(padding.x, g.FontSize*0.15f + text_base_offset_y), opened, 0.70f, false);
         if (g.LogEnabled)