Backends: SDL2, SDL3: don't attempt to call SDL_CaptureMouse() on drivers where we don't call SDL_GetGlobalMouseState(). (#8561)

This commit is contained in:
Zane van Iperen
2025-04-09 14:56:54 +02:00
committed by ocornut
parent 789de09dda
commit 74e453cf15
3 changed files with 49 additions and 36 deletions

View File

@@ -21,6 +21,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2025-04-09: Don't attempt to call SDL_CaptureMouse() on drivers where we don't call SDL_GetGlobalMouseState(). (#8561)
// 2025-03-21: Fill gamepad inputs and set ImGuiBackendFlags_HasGamepad regardless of ImGuiConfigFlags_NavEnableGamepad being set.
// 2025-03-10: When dealing with OEM keys, use scancodes instead of translated keycodes to choose ImGuiKey values. (#7136, #7201, #7206, #7306, #7670, #7672, #8468)
// 2025-02-26: Only start SDL_CaptureMouse() when mouse is being dragged, to mitigate issues with e.g.Linux debuggers not claiming capture back. (#6410, #3650)
@@ -142,6 +143,7 @@ struct ImGui_ImplSDL2_Data
SDL_Cursor* MouseLastCursor;
int MouseLastLeaveFrame;
bool MouseCanUseGlobalState;
bool MouseCanUseCapture;
// Gamepad handling
ImVector<SDL_GameController*> Gamepads;
@@ -474,17 +476,6 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
IMGUI_CHECKVERSION();
IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
// Check and store if we are on a SDL backend that supports global mouse position
// ("wayland" and "rpi" don't support it, but we chose to use a white-list instead of a black-list)
bool mouse_can_use_global_state = false;
#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
const char* sdl_backend = SDL_GetCurrentVideoDriver();
const char* global_mouse_whitelist[] = { "windows", "cocoa", "x11", "DIVE", "VMAN" };
for (int n = 0; n < IM_ARRAYSIZE(global_mouse_whitelist); n++)
if (strncmp(sdl_backend, global_mouse_whitelist[n], strlen(global_mouse_whitelist[n])) == 0)
mouse_can_use_global_state = true;
#endif
// Setup backend capabilities flags
ImGui_ImplSDL2_Data* bd = IM_NEW(ImGui_ImplSDL2_Data)();
io.BackendPlatformUserData = (void*)bd;
@@ -495,7 +486,18 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
bd->Window = window;
bd->WindowID = SDL_GetWindowID(window);
bd->Renderer = renderer;
bd->MouseCanUseGlobalState = mouse_can_use_global_state;
// Check and store if we are on a SDL backend that supports SDL_GetGlobalMouseState() and SDL_CaptureMouse()
// ("wayland" and "rpi" don't support it, but we chose to use a white-list instead of a black-list)
bd->MouseCanUseGlobalState = false;
bd->MouseCanUseCapture = false;
#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
const char* sdl_backend = SDL_GetCurrentVideoDriver();
const char* capture_and_global_state_whitelist[] = { "windows", "cocoa", "x11", "DIVE", "VMAN" };
for (const char* item : capture_and_global_state_whitelist)
if (strncmp(sdl_backend, item, strlen(item)) == 0)
bd->MouseCanUseGlobalState = bd->MouseCanUseCapture = true;
#endif
ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
platform_io.Platform_SetClipboardTextFn = ImGui_ImplSDL2_SetClipboardText;
@@ -630,12 +632,15 @@ static void ImGui_ImplSDL2_UpdateMouseData()
// We forward mouse input when hovered or captured (via SDL_MOUSEMOTION) or when focused (below)
#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
// - SDL_CaptureMouse() let the OS know e.g. that our drags can extend outside of parent boundaries (we want updated position) and shouldn't trigger other operations outside.
// - Debuggers under Linux tends to leave captured mouse on break, which may be very inconvenient, so to migitate the issue we wait until mouse has moved to begin capture.
bool want_capture = false;
for (int button_n = 0; button_n < ImGuiMouseButton_COUNT && !want_capture; button_n++)
if (ImGui::IsMouseDragging(button_n, 1.0f))
want_capture = true;
SDL_CaptureMouse(want_capture ? SDL_TRUE : SDL_FALSE);
// - Debuggers under Linux tends to leave captured mouse on break, which may be very inconvenient, so to mitigate the issue we wait until mouse has moved to begin capture.
if (bd->MouseCanUseCapture)
{
bool want_capture = false;
for (int button_n = 0; button_n < ImGuiMouseButton_COUNT && !want_capture; button_n++)
if (ImGui::IsMouseDragging(button_n, 1.0f))
want_capture = true;
SDL_CaptureMouse(want_capture ? SDL_TRUE : SDL_FALSE);
}
SDL_Window* focused_window = SDL_GetKeyboardFocus();
const bool is_app_focused = (bd->Window == focused_window);