Nav: Allow to collapse tree nodes with NavLeft and open them with NavRight (#787, #1079)

imgui.cpp

@@ -7044,14 +7044,31 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
     ImGuiButtonFlags button_flags = ImGuiButtonFlags_NoKeyModifiers | ((flags & ImGuiTreeNodeFlags_AllowOverlapMode) ? ImGuiButtonFlags_AllowOverlapMode : 0);
     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_Leaf))
+    if (!(flags & ImGuiTreeNodeFlags_Leaf))
+    {
+        bool toggled = false;
+        if (pressed)
         {
-        bool toggled = !(flags & (ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick)) || (g.NavActivateId == id);
+            toggled = !(flags & (ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick)) || (g.NavActivateId == id);
             if (flags & ImGuiTreeNodeFlags_OpenOnArrow)
                 toggled |= IsMouseHoveringRect(interact_bb.Min, ImVec2(interact_bb.Min.x + text_offset_x, interact_bb.Max.y)) && (!g.NavDisableMouseHover);
             if (flags & ImGuiTreeNodeFlags_OpenOnDoubleClick)
                 toggled |= g.IO.MouseDoubleClicked[0];
+        }
+
+        if (g.NavId == id && g.NavMoveRequest && g.NavMoveDir == ImGuiDir_Left && is_open)
+        {
+            toggled = true;
+            g.NavMoveRequest = false;
+        }
+        if (g.NavId == id && g.NavMoveRequest && g.NavMoveDir == ImGuiDir_Right && !is_open) // If there's something upcoming on the line we may want to give it the priority?
+        {
+            toggled = true;
+            g.NavMoveRequest = false;
+        }
+
         if (toggled)
         {
             is_open = !is_open;

imgui_demo.cpp

@@ -456,9 +456,9 @@ void ImGui::ShowTestWindow(bool* p_open)
         if (ImGui::TreeNode("Collapsing Headers"))
         {
             static bool closable_group = true;
+            ImGui::Checkbox("Enable extra group", &closable_group);
             if (ImGui::CollapsingHeader("Header"))
             {
-                ImGui::Checkbox("Enable extra group", &closable_group);
                 for (int i = 0; i < 5; i++)
                     ImGui::Text("Some content %d", i);
             }