Added TreeAdvanceToLabelPos() (#581)

imgui.cpp

@@ -6043,19 +6043,20 @@ bool ImGui::TreeNode(const char* label)
     ImGuiWindow* window = GetCurrentWindow();
     if (window->SkipItems)
         return false;
-
     return TreeNodeBehavior(window->GetID(label), 0, label, NULL);
 }
 
-float ImGui::GetTreeNodeToLabelSpacing(ImGuiTreeNodeFlags flags)
+void ImGui::TreeAdvanceToLabelPos()
 {
     ImGuiContext& g = *GImGui;
-    float off_from_start;
-    if (flags & ImGuiTreeNodeFlags_Framed)
-        off_from_start = g.FontSize + (g.Style.FramePadding.x * 3.0f) - ((float)(int)(g.CurrentWindow->WindowPadding.x*0.5f) - 1);
-    else
-        off_from_start = g.FontSize + (g.Style.FramePadding.x * 2.0f);
-    return off_from_start;
+    g.CurrentWindow->DC.CursorPos.x += GetTreeNodeToLabelSpacing();
+}
+
+// Horizontal distance preceeding label when using TreeNode() or Bullet()
+float ImGui::GetTreeNodeToLabelSpacing()
+{
+    ImGuiContext& g = *GImGui;
+    return g.FontSize + (g.Style.FramePadding.x * 2.0f);
 }
 
 void ImGui::SetNextTreeNodeOpen(bool is_open, ImGuiSetCond cond)

imgui.h

@@ -326,8 +326,9 @@ namespace ImGui
     IMGUI_API void          TreePush(const char* str_id = NULL);                                    // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
     IMGUI_API void          TreePush(const void* ptr_id = NULL);                                    // "
     IMGUI_API void          TreePop();                                                              // ~ Unindent()+PopId()
+    IMGUI_API void          TreeAdvanceToLabelPos();                                                // advance cursor x position by GetTreeNodeToLabelSpacing()
+    IMGUI_API float         GetTreeNodeToLabelSpacing();                                            // horizontal distance preceeding label when using TreeNode*() or Bullet() == (g.FontSize + style.FramePadding.x*2) for a regular unframed TreeNode
     IMGUI_API void          SetNextTreeNodeOpen(bool is_open, ImGuiSetCond cond = 0);               // set next TreeNode/CollapsingHeader open state.
-    IMGUI_API float         GetTreeNodeToLabelSpacing(ImGuiTreeNodeFlags flags = 0);                // return horizontal distance between cursor and text label due to collapsing node. == (g.FontSize + style.FramePadding.x*2) for a regular unframed TreeNode
     IMGUI_API bool          CollapsingHeader(const char* label, ImGuiTreeNodeFlags flags = 0);      // if returning 'true' the header is open. user doesn't have to call TreePop().
     IMGUI_API bool          CollapsingHeader(const char* label, bool* p_open, ImGuiTreeNodeFlags flags = 0); // when 'p_open' isn't NULL, display an additional small close button on upper right of the header
 

imgui_demo.cpp

@@ -275,10 +275,8 @@ void ImGui::ShowTestWindow(bool* p_open)
                     }
                     else
                     {
-                        // Leaf: Here we use the ImGuiTreeNodeFlags_Leaf functionality + ImGuiTreeNodeFlags_NoTreePushOnOpen to avoid testing return value and doing a TreePop
-                        // The only reason we have a TreeNode at all is to allow selection of the leaf. Otherwise we can use BulletText() or a simple Text() element offset by GetTreeNodeToLabelSpacing()
-                        node_flags |= ImGuiTreeNodeFlags_Leaf|ImGuiTreeNodeFlags_NoTreePushOnOpen;
-                        ImGui::TreeNodeEx((void*)(intptr_t)i, node_flags, "Selectable Leaf %d", i);
+                        // Leaf: The only reason we have a TreeNode at all is to allow selection of the leaf. Otherwise we can use BulletText() or TreeAdvanceToLabelPos()+Text().
+                        ImGui::TreeNodeEx((void*)(intptr_t)i, node_flags | ImGuiTreeNodeFlags_Leaf | ImGuiTreeNodeFlags_NoTreePushOnOpen, "Selectable Leaf %d", i);
                         if (ImGui::IsItemClicked()) 
                             node_clicked = i;
                     }