IO: Added SetAppAcceptingEvents() function (#4921, #4858)

docs/CHANGELOG.txt

@@ -65,6 +65,9 @@ Other Changes:
   or interacting with a game/3D view).
 - IO: Fixed input queue trickling of mouse wheel events: multiple wheel events are merged, while
   a mouse pos followed by a mouse wheel are now trickled. (#4921, #4821)
+- IO: Added io.SetAppAcceptingEvents() to set a master flag for accepting key/mouse/characters
+  events (default to true). Useful if you have native dialog boxes that are interrupting your
+  application loop/refresh, and you want to disable events being queued while your app is frozen.
 - Windows: Fixed first-time windows appearing in negative coordinates from being initialized
   with a wrong size. This would most often be noticeable in multi-viewport mode (docking branch)
   when spawning a window in a monitor with negative coordinates. (#5215, #3414) [@DimaKoltun]

imgui.cpp

@@ -1169,6 +1169,7 @@ ImGuiIO::ImGuiIO()
     for (int i = 0; i < IM_ARRAYSIZE(MouseDownDuration); i++) MouseDownDuration[i] = MouseDownDurationPrev[i] = -1.0f;
     for (int i = 0; i < IM_ARRAYSIZE(KeysData); i++) { KeysData[i].DownDuration = KeysData[i].DownDurationPrev = -1.0f; }
     for (int i = 0; i < IM_ARRAYSIZE(NavInputsDownDuration); i++) NavInputsDownDuration[i] = -1.0f;
+    AppAcceptingEvents = true;
     BackendUsingLegacyKeyArrays = (ImS8)-1;
     BackendUsingLegacyNavInputArray = true; // assume using legacy array until proven wrong
 }
@@ -1181,7 +1182,7 @@ void ImGuiIO::AddInputCharacter(unsigned int c)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(&g.IO == this && "Can only add events to current context.");
-    if (c == 0)
+    if (c == 0 || !AppAcceptingEvents)
         return;
 
     ImGuiInputEvent e;
@@ -1195,7 +1196,7 @@ void ImGuiIO::AddInputCharacter(unsigned int c)
 // we should save the high surrogate.
 void ImGuiIO::AddInputCharacterUTF16(ImWchar16 c)
 {
-    if (c == 0 && InputQueueSurrogate == 0)
+    if ((c == 0 && InputQueueSurrogate == 0) || !AppAcceptingEvents)
         return;
 
     if ((c & 0xFC00) == 0xD800) // High surrogate, must save
@@ -1229,6 +1230,8 @@ void ImGuiIO::AddInputCharacterUTF16(ImWchar16 c)
 
 void ImGuiIO::AddInputCharactersUTF8(const char* utf8_chars)
 {
+    if (!AppAcceptingEvents)
+        return;
     while (*utf8_chars != 0)
     {
         unsigned int c = 0;
@@ -1267,7 +1270,7 @@ void ImGuiIO::ClearInputKeys()
 void ImGuiIO::AddKeyAnalogEvent(ImGuiKey key, bool down, float analog_value)
 {
     //if (e->Down) { IMGUI_DEBUG_LOG("AddKeyEvent() Key='%s' %d, NativeKeycode = %d, NativeScancode = %d\n", ImGui::GetKeyName(e->Key), e->Down, e->NativeKeycode, e->NativeScancode); }
-    if (key == ImGuiKey_None)
+    if (key == ImGuiKey_None || !AppAcceptingEvents)
         return;
     ImGuiContext& g = *GImGui;
     IM_ASSERT(&g.IO == this && "Can only add events to current context.");
@@ -1308,6 +1311,8 @@ void ImGuiIO::AddKeyAnalogEvent(ImGuiKey key, bool down, float analog_value)
 
 void ImGuiIO::AddKeyEvent(ImGuiKey key, bool down)
 {
+    if (!AppAcceptingEvents)
+        return;
     AddKeyAnalogEvent(key, down, down ? 1.0f : 0.0f);
 }
 
@@ -1336,11 +1341,19 @@ void ImGuiIO::SetKeyEventNativeData(ImGuiKey key, int native_keycode, int native
 #endif
 }
 
+// Set master flag for accepting key/mouse/text events (default to true). Useful if you have native dialog boxes that are interrupting your application loop/refresh, and you want to disable events being queued while your app is frozen.
+void ImGuiIO::SetAppAcceptingEvents(bool accepting_events)
+{
+    AppAcceptingEvents = accepting_events;
+}
+
 // Queue a mouse move event
 void ImGuiIO::AddMousePosEvent(float x, float y)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(&g.IO == this && "Can only add events to current context.");
+    if (!AppAcceptingEvents)
+        return;
 
     ImGuiInputEvent e;
     e.Type = ImGuiInputEventType_MousePos;
@@ -1355,6 +1368,8 @@ void ImGuiIO::AddMouseButtonEvent(int mouse_button, bool down)
     ImGuiContext& g = *GImGui;
     IM_ASSERT(&g.IO == this && "Can only add events to current context.");
     IM_ASSERT(mouse_button >= 0 && mouse_button < ImGuiMouseButton_COUNT);
+    if (!AppAcceptingEvents)
+        return;
 
     ImGuiInputEvent e;
     e.Type = ImGuiInputEventType_MouseButton;
@@ -1369,7 +1384,7 @@ void ImGuiIO::AddMouseWheelEvent(float wheel_x, float wheel_y)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(&g.IO == this && "Can only add events to current context.");
-    if (wheel_x == 0.0f && wheel_y == 0.0f)
+    if ((wheel_x == 0.0f && wheel_y == 0.0f) || !AppAcceptingEvents)
         return;
 
     ImGuiInputEvent e;

imgui.h

@@ -65,7 +65,7 @@ Index of this file:
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.88 WIP"
-#define IMGUI_VERSION_NUM           18725
+#define IMGUI_VERSION_NUM           18726
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 
@@ -1975,9 +1975,10 @@ struct ImGuiIO
     IMGUI_API void  AddInputCharacterUTF16(ImWchar16 c);                    // Queue a new character input from an UTF-16 character, it can be a surrogate
     IMGUI_API void  AddInputCharactersUTF8(const char* str);                // Queue a new characters input from an UTF-8 string
 
+    IMGUI_API void  SetKeyEventNativeData(ImGuiKey key, int native_keycode, int native_scancode, int native_legacy_index = -1); // [Optional] Specify index for legacy <1.87 IsKeyXXX() functions with native indices + specify native keycode, scancode.
+    IMGUI_API void  SetAppAcceptingEvents(bool accepting_events);           // Set master flag for accepting key/mouse/text events (default to true). Useful if you have native dialog boxes that are interrupting your application loop/refresh, and you want to disable events being queued while your app is frozen.
     IMGUI_API void  ClearInputCharacters();                                 // [Internal] Clear the text input buffer manually
     IMGUI_API void  ClearInputKeys();                                       // [Internal] Release all keys
-    IMGUI_API void  SetKeyEventNativeData(ImGuiKey key, int native_keycode, int native_scancode, int native_legacy_index = -1); // [Optional] Specify index for legacy <1.87 IsKeyXXX() functions with native indices + specify native keycode, scancode.
 
     //------------------------------------------------------------------
     // Output - Updated by NewFrame() or EndFrame()/Render()
@@ -2044,7 +2045,8 @@ struct ImGuiIO
     float       NavInputsDownDuration[ImGuiNavInput_COUNT];
     float       NavInputsDownDurationPrev[ImGuiNavInput_COUNT];
     float       PenPressure;                        // Touch/Pen pressure (0.0f to 1.0f, should be >0.0f only when MouseDown[0] == true). Helper storage currently unused by Dear ImGui.
-    bool        AppFocusLost;
+    bool        AppFocusLost;                       // Only modify via AddFocusEvent()
+    bool        AppAcceptingEvents;                 // Only modify via SetAppAcceptingEvents()
     ImS8        BackendUsingLegacyKeyArrays;        // -1: unknown, 0: using AddKeyEvent(), 1: using legacy io.KeysDown[]
     bool        BackendUsingLegacyNavInputArray;    // 0: using AddKeyAnalogEvent(), 1: writing to legacy io.NavInputs[] directly
     ImWchar16   InputQueueSurrogate;                // For AddInputCharacterUTF16()