Factoring bits out of Begin() into a private CreateNewWindow() funciton

(Hopefully to ease a bit the merging work for ProDBG)

imgui.cpp

@@ -303,7 +303,6 @@ static bool         IsKeyPressedMap(ImGuiKey key, bool repeat = true);
 
 static bool         CloseWindowButton(bool* p_opened = NULL);
 static void         FocusWindow(ImGuiWindow* window);
-static ImGuiWindow* FindWindow(const char* name);
 static ImGuiWindow* FindHoveredWindow(ImVec2 pos, bool excluding_childs);
 
 //-----------------------------------------------------------------------------
@@ -2060,15 +2059,6 @@ int ImGui::GetFrameCount()
     return GImGui.FrameCount;
 }
 
-static ImGuiWindow* FindWindow(const char* name)
-{
-    ImGuiState& g = GImGui;
-    for (size_t i = 0; i != g.Windows.size(); i++)
-        if (strcmp(g.Windows[i]->Name, name) == 0)
-            return g.Windows[i];
-    return NULL;
-}
-
 void ImGui::BeginTooltip()
 {
     ImGui::Begin("##Tooltip", NULL, ImVec2(0,0), 0.9f, ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoMove|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings|ImGuiWindowFlags_Tooltip);
@@ -2138,38 +2128,34 @@ void ImGui::EndChild()
     }
 }
 
-// Push a new ImGui window to add widgets to. 
+static ImGuiWindow* FindWindowByName(const char* name)
-// - A default window called "Debug" is automatically stacked at the beginning of every frame.
+{
-// - This can be called multiple times during the frame with the same window name to append content to the same window.
+    // FIXME-OPT: Consider optimizing this (e.g. sorted hashes to window pointers)
-// - The window name is used as a unique identifier to preserve window information across frames (and save rudimentary information to the .ini file). Note that you can use ## to append unique data that isn't displayed, e.g. "My window##1" will use "My window##1" as unique window ID but display "My window" to the user.
+    ImGuiState& g = GImGui;
-// - Return false when window is collapsed, so you can early out in your code. You always need to call ImGui::End() even if false is returned.
+    for (size_t i = 0; i != g.Windows.size(); i++)
-// - Passing 'bool* p_opened' displays a Close button on the upper-right corner of the window, the pointed value will be set to false when the button is pressed.
+        if (strcmp(g.Windows[i]->Name, name) == 0)
-// - Passing non-zero 'size' is roughly equivalent to calling SetNextWindowSize(size, ImGuiSetCondition_FirstUseEver) prior to calling Begin().
+            return g.Windows[i];
-bool ImGui::Begin(const char* name, bool* p_opened, ImVec2 size, float fill_alpha, ImGuiWindowFlags flags)
+    return NULL;
+}
+
+static ImGuiWindow* CreateNewWindow(const char* name, ImVec2 size, ImGuiWindowFlags flags)
 {
     ImGuiState& g = GImGui;
-    const ImGuiStyle& style = g.Style;
-    IM_ASSERT(g.Initialized);                       // Forgot to call ImGui::NewFrame()
-    IM_ASSERT(name != NULL);                        // Must pass a name
 
-    ImGuiWindow* window = FindWindow(name);
-    if (!window)
-    {
     // Create window the first time
+    ImGuiWindow* window = (ImGuiWindow*)ImGui::MemAlloc(sizeof(ImGuiWindow));
+    new(window) ImGuiWindow(name);
+    window->Flags = flags;
+
     if (flags & ImGuiWindowFlags_NoSavedSettings)
     {
-            // Tooltip and child windows don't store settings
+		// User can disable loading and saving of settings. Tooltip and child windows also don't store settings.
-            window = (ImGuiWindow*)ImGui::MemAlloc(sizeof(ImGuiWindow));
-            new(window) ImGuiWindow(name);
-            
         window->Size = window->SizeFull = size;
     }
     else
     {
-            // Normal windows store settings in .ini file
+        // Retrieve settings from .ini file
-            window = (ImGuiWindow*)ImGui::MemAlloc(sizeof(ImGuiWindow));
+		// Use SetWindowPos() or SetNextWindowPos() with the appropriate condition flag to change the initial position of a window.
-            new(window) ImGuiWindow(name);
-
         window->PosFloat = ImVec2(60, 60);
         window->Pos = ImVec2((float)(int)window->PosFloat.x, (float)(int)window->PosFloat.y);
 
@@ -2197,9 +2183,30 @@ bool ImGui::Begin(const char* name, bool* p_opened, ImVec2 size, float fill_alph
         window->Size = window->SizeFull = size;
     }
     g.Windows.push_back(window);
+    return window;
 }
+
+// Push a new ImGui window to add widgets to. 
+// - A default window called "Debug" is automatically stacked at the beginning of every frame.
+// - This can be called multiple times during the frame with the same window name to append content to the same window.
+// - The window name is used as a unique identifier to preserve window information across frames (and save rudimentary information to the .ini file). Note that you can use ## to append unique data that isn't displayed, e.g. "My window##1" will use "My window##1" as unique window ID but display "My window" to the user.
+// - Return false when window is collapsed, so you can early out in your code. You always need to call ImGui::End() even if false is returned.
+// - Passing 'bool* p_opened' displays a Close button on the upper-right corner of the window, the pointed value will be set to false when the button is pressed.
+// - Passing non-zero 'size' is roughly equivalent to calling SetNextWindowSize(size, ImGuiSetCondition_FirstUseEver) prior to calling Begin().
+bool ImGui::Begin(const char* name, bool* p_opened, ImVec2 size, float fill_alpha, ImGuiWindowFlags flags)
+{
+    ImGuiState& g = GImGui;
+    const ImGuiStyle& style = g.Style;
+    IM_ASSERT(g.Initialized);                       // Forgot to call ImGui::NewFrame()
+    IM_ASSERT(name != NULL);                        // Must pass a name
+
+    // Find or create
+    ImGuiWindow* window = FindWindowByName(name);
+    if (!window)
+        window = CreateNewWindow(name, size, flags);
     window->Flags = (ImGuiWindowFlags)flags;
 
+    // Add to stack
     g.CurrentWindowStack.push_back(window);
     g.CurrentWindow = window;
 
@@ -2222,7 +2229,7 @@ bool ImGui::Begin(const char* name, bool* p_opened, ImVec2 size, float fill_alph
         g.SetNextWindowCollapsedCond = 0;
     }
 
-    // Find root
+    // Find root (if we are a child window)
     size_t root_idx = g.CurrentWindowStack.size() - 1;
     while (root_idx > 0)
     {

imgui.h

@@ -161,10 +161,10 @@ namespace ImGui
     IMGUI_API ImVec2        GetWindowSize();                                                    // get current window position.
     IMGUI_API float         GetWindowWidth();
     IMGUI_API bool          GetWindowCollapsed();
-    IMGUI_API void          SetWindowPos(const ImVec2& pos, ImGuiSetCondition cond = 0);        // set current window position.
+    IMGUI_API void          SetWindowPos(const ImVec2& pos, ImGuiSetCondition cond = 0);        // set current window position - call within Begin()/End().
     IMGUI_API void          SetWindowSize(const ImVec2& size, ImGuiSetCondition cond = 0);      // set current window size. set to ImVec2(0,0) to force an auto-fit
     IMGUI_API void          SetWindowCollapsed(bool collapsed, ImGuiSetCondition cond = 0);     // set current window collapsed state.
-    IMGUI_API void          SetNextWindowPos(const ImVec2& pos, ImGuiSetCondition cond = 0);    // set next window position.
+    IMGUI_API void          SetNextWindowPos(const ImVec2& pos, ImGuiSetCondition cond = 0);    // set next window position - call before Begin().
     IMGUI_API void          SetNextWindowSize(const ImVec2& size, ImGuiSetCondition cond = 0);  // set next window size. set to ImVec2(0,0) to force an auto-fit
     IMGUI_API void          SetNextWindowCollapsed(bool collapsed, ImGuiSetCondition cond = 0); // set next window collapsed state.