Made with the NoResize flag can still use auto-fitting. Added SetWindowSize().

imgui.cpp

@@ -1023,7 +1023,7 @@ ImGuiWindow::ImGuiWindow(const char* name, ImVec2 default_pos, ImVec2 default_si
     FontWindowScale = 1.0f;
 
     if (ImLength(Size) < 0.001f)
-        AutoFitFrames = 3;
+        AutoFitFrames = 2;
 
     DrawList = (ImDrawList*)ImGui::MemAlloc(sizeof(ImDrawList));
     new(DrawList) ImDrawList();
@@ -2170,15 +2170,8 @@ bool Begin(const char* name, bool* open, ImVec2 size, float fill_alpha, ImGuiWin
                     window->SizeFull = window->SizeContentsFit + g.Style.WindowPadding - ImVec2(0.0f, g.Style.ItemSpacing.y);
                 }
             }
-            else if (!(window->Flags & ImGuiWindowFlags_NoResize))
+            else
             {
-                // Draw resize grip
-                const ImGuiAabb resize_aabb(window->Aabb().GetBR()-ImVec2(18,18), window->Aabb().GetBR());
-                const ImGuiID resize_id = window->GetID("#RESIZE");
-                bool hovered, held;
-                ButtonBehaviour(resize_aabb, resize_id, &hovered, &held, true);
-                resize_col = window->Color(held ? ImGuiCol_ResizeGripActive : hovered ? ImGuiCol_ResizeGripHovered : ImGuiCol_ResizeGrip);
-
                 ImVec2 size_auto_fit = ImClamp(window->SizeContentsFit + style.AutoFitPadding, style.WindowMinSize, g.IO.DisplaySize - style.AutoFitPadding);
                 if (window->AutoFitFrames > 0)
                 {
@@ -2186,7 +2179,16 @@ bool Begin(const char* name, bool* open, ImVec2 size, float fill_alpha, ImGuiWin
                     window->SizeFull = ImMax(window->SizeFull, size_auto_fit);
                     MarkSettingsDirty();
                 }
-                else if (g.HoveredWindow == window && held && g.IO.MouseDoubleClicked[0])
+                else if (!(window->Flags & ImGuiWindowFlags_NoResize))
+                {
+                    // Resize grip
+                    const ImGuiAabb resize_aabb(window->Aabb().GetBR()-ImVec2(18,18), window->Aabb().GetBR());
+                    const ImGuiID resize_id = window->GetID("#RESIZE");
+                    bool hovered, held;
+                    ButtonBehaviour(resize_aabb, resize_id, &hovered, &held, true);
+                    resize_col = window->Color(held ? ImGuiCol_ResizeGripActive : hovered ? ImGuiCol_ResizeGripHovered : ImGuiCol_ResizeGrip);
+
+                    if (g.HoveredWindow == window && held && g.IO.MouseDoubleClicked[0])
                     {
                         // Manual auto-fit
                         window->SizeFull = size_auto_fit;
@@ -2200,6 +2202,7 @@ bool Begin(const char* name, bool* open, ImVec2 size, float fill_alpha, ImGuiWin
                         window->Size = window->SizeFull;
                         MarkSettingsDirty();
                     }
+                }
 
                 // Update aabb immediately so that the rendering below isn't one frame late
                 title_bar_aabb = window->TitleBarAabb();
@@ -2565,6 +2568,14 @@ ImVec2 GetWindowSize()
     return window->Size;
 }
 
+void SetWindowSize(const ImVec2& size)
+{
+    ImGuiWindow* window = GetCurrentWindow();
+    window->SizeFull = size;
+    if (ImLength(size) < 0.001f)
+        window->AutoFitFrames = 3;
+}
+
 ImVec2 GetWindowContentRegionMin()
 {
     ImGuiWindow* window = GetCurrentWindow();

imgui.h

@@ -146,6 +146,7 @@ namespace ImGui
     bool        GetWindowIsFocused();
     ImVec2      GetWindowSize();
     float       GetWindowWidth();
+    void		SetWindowSize(const ImVec2& size);                                  // set to ImVec2(0,0) to force an auto-fit
     ImVec2      GetWindowPos();                                                     // you should rarely need/care about the window position, but it can be useful if you want to use your own drawing.
     void        SetWindowPos(const ImVec2& pos);                                    // set current window pos.
     ImVec2      GetWindowContentRegionMin();