TreeNodeEx(): ImGuiTreeNodeFlags_AlwaysOpen->ImGuiTreeNodeFlags_Leaf, + added ImGuiTreeNodeFlags_Bullet (#324, #581)

imgui.cpp

@@ -5776,7 +5776,7 @@ void ImGui::LogButtons()
 
 bool ImGui::TreeNodeBehaviorIsOpen(ImGuiID id, ImGuiTreeNodeFlags flags)
 {
-    if (flags & ImGuiTreeNodeFlags_AlwaysOpen)
+    if (flags & ImGuiTreeNodeFlags_Leaf)
         return true;
 
     // We only write to the tree storage if the user clicks (or explicitely use SetNextTreeNode*** functions)
@@ -5871,7 +5871,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
     if (flags & ImGuiTreeNodeFlags_OpenOnDoubleClick)
         button_flags |= ImGuiButtonFlags_PressedOnDoubleClick | ((flags & ImGuiTreeNodeFlags_OpenOnArrow) ? ImGuiButtonFlags_PressedOnClickRelease : 0);
     bool hovered, held, pressed = ButtonBehavior(interact_bb, id, &hovered, &held, button_flags);
-    if (pressed && !(flags & ImGuiTreeNodeFlags_AlwaysOpen))
+    if (pressed && !(flags & ImGuiTreeNodeFlags_Leaf))
     {
         bool toggled = !(flags & (ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick));
         if (flags & ImGuiTreeNodeFlags_OpenOnArrow)
@@ -5915,9 +5915,9 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
         if (hovered || (flags & ImGuiTreeNodeFlags_Selected))
             RenderFrame(bb.Min, bb.Max, col, false);
 
-        if (flags & ImGuiTreeNodeFlags_AlwaysOpen)
+        if (flags & ImGuiTreeNodeFlags_Bullet)
             RenderBullet(bb.Min + ImVec2(text_offset_x * 0.5f, g.FontSize*0.50f + text_base_offset_y));
-        else
+        else if (!(flags & ImGuiTreeNodeFlags_Leaf))
             RenderCollapseTriangle(bb.Min + ImVec2(padding.x, g.FontSize*0.15f + text_base_offset_y), is_open, 0.70f, false);
         if (g.LogEnabled)
             LogRenderedText(text_pos, ">");

imgui.h

@@ -541,10 +541,11 @@ enum ImGuiTreeNodeFlags_
     ImGuiTreeNodeFlags_DefaultOpen          = 1 << 5,   // Default node to be open
     ImGuiTreeNodeFlags_OpenOnDoubleClick    = 1 << 6,   // Need double-click to open node
     ImGuiTreeNodeFlags_OpenOnArrow          = 1 << 7,   // Only open when clicking on the arrow part. If ImGuiTreeNodeFlags_OpenOnDoubleClick is also set, single-click arrow or double-click all box to open.
-    ImGuiTreeNodeFlags_AlwaysOpen           = 1 << 8,   // No collapsing, no arrow (use as a convenience for leaf nodes). 
-    //ImGuiTreeNodeFlags_UnindentArrow      = 1 << 9,   // FIXME: TODO: Unindent tree so that Label is aligned to current X position
-    //ImGuITreeNodeFlags_SpanAllAvailWidth  = 1 << 10,  // FIXME: TODO: Extend hit box horizontally even if not framed
-    //ImGuiTreeNodeFlags_NoScrollOnOpen     = 1 << 11,  // FIXME: TODO: Automatically scroll on TreePop() if node got just open and contents is not visible
+    ImGuiTreeNodeFlags_Leaf                 = 1 << 8,   // No collapsing, no arrow (use as a convenience for leaf nodes). 
+    ImGuiTreeNodeFlags_Bullet               = 1 << 9,   // Display a bullet instead of arrow
+    //ImGuiTreeNodeFlags_UnindentArrow      = 1 << 10,  // FIXME: TODO: Unindent tree so that Label is aligned to current X position
+    //ImGuITreeNodeFlags_SpanAllAvailWidth  = 1 << 11,  // FIXME: TODO: Extend hit box horizontally even if not framed
+    //ImGuiTreeNodeFlags_NoScrollOnOpen     = 1 << 12,  // FIXME: TODO: Automatically scroll on TreePop() if node got just open and contents is not visible
     ImGuiTreeNodeFlags_CollapsingHeader     = ImGuiTreeNodeFlags_Framed | ImGuiTreeNodeFlags_NoAutoOpenOnLog
 };
 

imgui_demo.cpp

@@ -253,32 +253,45 @@ void ImGui::ShowTestWindow(bool* p_open)
 
             if (ImGui::TreeNode("With selectable nodes"))
             {
-                ShowHelpMarker("Click to select, CTRL+Click to toggle, click on arrows to open");
-                static int selection_mask = 0x02;   // Dumb representation of what may be user-side selection state. You may carry selection state inside or outside your objects in whatever format you see fit.
-                int node_clicked = -1;
+                ShowHelpMarker("This is a more standard looking tree with selectable nodes.\nClick to select, CTRL+Click to toggle, click on arrows or double-click to open.");
+                ImGui::PushStyleVar(ImGuiStyleVar_IndentSpacing, ImGui::GetFontSize()*3); // Increase spacing to differentiate leaves from expanded contents.
+                static int selection_mask = (1 << 2); // Dumb representation of what may be user-side selection state. You may carry selection state inside or outside your objects in whatever format you see fit.
+                int node_clicked = -1;                // Temporary storage of what node we have clicked to process selection at the end of the loop. May be a pointer to your own node type, etc.
                 for (int i = 0; i < 6; i++)
                 {
+                    // Disable the default open on single-click behavior and pass in Selected flag according to our selection state.
                     ImGuiTreeNodeFlags node_flags = ((selection_mask & (1 << i)) ? ImGuiTreeNodeFlags_Selected : 0) | ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick;
-                    if (i >= 3)
-                        node_flags |= ImGuiTreeNodeFlags_AlwaysOpen;
-                    bool node_open = ImGui::TreeNodeEx((void*)(intptr_t)i, node_flags, "Selectable %s %d", (i >= 3) ? "Leaf" : "Node", i);
+                    if (i < 3)
+                    {
+                        // Node
+                        bool node_open = ImGui::TreeNodeEx((void*)(intptr_t)i, node_flags, "Selectable Node %d", i);
                         if (ImGui::IsItemClicked()) 
                             node_clicked = i;
                         if (node_open)
                         {
-                        ImGui::Text("Selectable Blah blah");
-                        ImGui::Text("Blah blah");
+                            ImGui::Text("Blah blah\nBlah Blah");
                             ImGui::TreePop();
                         }
                     }
+                    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);
+                        if (ImGui::IsItemClicked()) 
+                            node_clicked = i;
+                    }
+                }
                 if (node_clicked != -1)
                 {
                     // Update selection state. Process outside of tree loop to avoid visual inconsistencies during the clicking-frame.
                     if (ImGui::GetIO().KeyCtrl)
                         selection_mask ^= (1 << node_clicked);          // CTRL+click to toggle
-                    else if (!(selection_mask & (1 << node_clicked)))   // If there is already a selection don't replace we clicked node is part of it
+                    else //if (!(selection_mask & (1 << node_clicked))) // Depending on selection behavior you want, this commented bit preserve selection when clicking on item that is part of the selection
                         selection_mask = (1 << node_clicked);           // Click to single-select
                 }
+                ImGui::PopStyleVar();
                 ImGui::TreePop();
             }
             ImGui::TreePop();