Settings: Added ReadInitFn pre-load handler.

(docking branch already has it, so it'll probably conflict with same contents)

imgui.cpp

@@ -918,9 +918,9 @@ static ImRect           GetViewportRect();
 
 // Settings
 static void             WindowSettingsHandler_ClearAll(ImGuiContext*, ImGuiSettingsHandler*);
-static void             WindowSettingsHandler_ApplyAll(ImGuiContext*, ImGuiSettingsHandler*);
 static void*            WindowSettingsHandler_ReadOpen(ImGuiContext*, ImGuiSettingsHandler*, const char* name);
 static void             WindowSettingsHandler_ReadLine(ImGuiContext*, ImGuiSettingsHandler*, void* entry, const char* line);
+static void             WindowSettingsHandler_ApplyAll(ImGuiContext*, ImGuiSettingsHandler*);
 static void             WindowSettingsHandler_WriteAll(ImGuiContext*, ImGuiSettingsHandler*, ImGuiTextBuffer* buf);
 
 // Platform Dependents default implementation for IO functions
@@ -3945,9 +3945,9 @@ void ImGui::Initialize(ImGuiContext* context)
         ini_handler.TypeName = "Window";
         ini_handler.TypeHash = ImHashStr("Window");
         ini_handler.ClearAllFn = WindowSettingsHandler_ClearAll;
-        ini_handler.ApplyAllFn = WindowSettingsHandler_ApplyAll;
         ini_handler.ReadOpenFn = WindowSettingsHandler_ReadOpen;
         ini_handler.ReadLineFn = WindowSettingsHandler_ReadLine;
+        ini_handler.ApplyAllFn = WindowSettingsHandler_ApplyAll;
         ini_handler.WriteAllFn = WindowSettingsHandler_WriteAll;
         g.SettingsHandlers.push_back(ini_handler);
     }
@@ -9784,6 +9784,12 @@ void ImGui::LoadIniSettingsFromMemory(const char* ini_data, size_t ini_size)
     memcpy(buf, ini_data, ini_size);
     buf_end[0] = 0;
 
+    // Call pre-read handlers
+    // Some types will clear their data (e.g. dock information) some types will allow merge/override (window)
+    for (int handler_n = 0; handler_n < g.SettingsHandlers.Size; handler_n++)
+        if (g.SettingsHandlers[handler_n].ReadInitFn)
+            g.SettingsHandlers[handler_n].ReadInitFn(&g, &g.SettingsHandlers[handler_n]);
+
     void* entry_data = NULL;
     ImGuiSettingsHandler* entry_handler = NULL;
 
@@ -9872,24 +9878,12 @@ static void WindowSettingsHandler_ClearAll(ImGuiContext* ctx, ImGuiSettingsHandl
     g.SettingsWindows.clear();
 }
 
-// Apply to existing windows (if any)
-static void WindowSettingsHandler_ApplyAll(ImGuiContext* ctx, ImGuiSettingsHandler*)
-{
-    ImGuiContext& g = *ctx;
-    for (ImGuiWindowSettings* settings = g.SettingsWindows.begin(); settings != NULL; settings = g.SettingsWindows.next_chunk(settings))
-        if (settings->WantApply)
-        {
-            if (ImGuiWindow* window = ImGui::FindWindowByID(settings->ID))
-                ApplyWindowSettings(window, settings);
-            settings->WantApply = false;
-        }
-}
-
 static void* WindowSettingsHandler_ReadOpen(ImGuiContext*, ImGuiSettingsHandler*, const char* name)
 {
-    ImGuiWindowSettings* settings = ImGui::FindWindowSettings(ImHashStr(name));
-    if (!settings)
-        settings = ImGui::CreateNewWindowSettings(name);
+    ImGuiWindowSettings* settings = ImGui::FindOrCreateWindowSettings(name);
+    ImGuiID id = settings->ID;
+    *settings = ImGuiWindowSettings(); // Clear existing if recycling previous entry
+    settings->ID = id;
     settings->WantApply = true;
     return (void*)settings;
 }
@@ -9904,6 +9898,19 @@ static void WindowSettingsHandler_ReadLine(ImGuiContext*, ImGuiSettingsHandler*,
     else if (sscanf(line, "Collapsed=%d", &i) == 1)     settings->Collapsed = (i != 0);
 }
 
+// Apply to existing windows (if any)
+static void WindowSettingsHandler_ApplyAll(ImGuiContext* ctx, ImGuiSettingsHandler*)
+{
+    ImGuiContext& g = *ctx;
+    for (ImGuiWindowSettings* settings = g.SettingsWindows.begin(); settings != NULL; settings = g.SettingsWindows.next_chunk(settings))
+        if (settings->WantApply)
+        {
+            if (ImGuiWindow* window = ImGui::FindWindowByID(settings->ID))
+                ApplyWindowSettings(window, settings);
+            settings->WantApply = false;
+        }
+}
+
 static void WindowSettingsHandler_WriteAll(ImGuiContext* ctx, ImGuiSettingsHandler* handler, ImGuiTextBuffer* buf)
 {
     // Gather data from windows that were active during this session

imgui_internal.h

@@ -1082,9 +1082,10 @@ struct ImGuiSettingsHandler
     const char* TypeName;       // Short description stored in .ini file. Disallowed characters: '[' ']'
     ImGuiID     TypeHash;       // == ImHashStr(TypeName)
     void        (*ClearAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Clear all settings data
-    void        (*ApplyAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Read: Called after reading (in registration order)
+    void        (*ReadInitFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Read: Called before reading (in registration order)
     void*       (*ReadOpenFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, const char* name);              // Read: Called when entering into a new ini entry e.g. "[Window][Name]"
     void        (*ReadLineFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, void* entry, const char* line); // Read: Called for every line of text within an ini entry
+    void        (*ApplyAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler);                                // Read: Called after reading (in registration order)
     void        (*WriteAllFn)(ImGuiContext* ctx, ImGuiSettingsHandler* handler, ImGuiTextBuffer* out_buf);      // Write: Output every entries into 'out_buf'
     void*       UserData;