Backends: SDL2: Mouse position is correctly reported when the host platform window is hovered but not focused. (#2445, #3751, #4377)

(requires SDL 2.0.5 because SDL_GetMouseFocus() is only usable with SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH).
This commit is contained in:
ocornut
2021-07-29 18:21:08 +02:00
parent c720075c67
commit 1cdd110eb4
2 changed files with 31 additions and 6 deletions

View File

@ -1,7 +1,7 @@
// dear imgui: Platform Backend for SDL2
// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
// (Info: SDL2 is a cross-platform general purpose library for handling windows, inputs, graphics context creation, etc.)
// (Requires: SDL 2.0. Prefer SDL 2.0.4+ for full feature support.)
// (Prefer SDL 2.0.5+ for full feature support.)
// Implemented features:
// [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
@ -18,7 +18,8 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2021-06:29: *BREAKING CHANGE* Removed 'SDL_Window* window' parameter to ImGui_ImplSDL2_NewFrame() which was unnecessary.
// 2021-07-29: Inputs: MousePos is correctly reported when the host platform window is hovered but not focused (using SDL_GetMouseFocus() + SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, requires SDL 2.0.5+)
// 2021-06-29: *BREAKING CHANGE* Removed 'SDL_Window* window' parameter to ImGui_ImplSDL2_NewFrame() which was unnecessary.
// 2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
// 2021-03-22: Rework global mouse pos availability check listing supported platforms explicitly, effectively fixing mouse access on Raspberry Pi. (#2837, #3950)
// 2020-05-25: Misc: Report a zero display-size when window is minimized, to be consistent with other backends.
@ -59,6 +60,7 @@
#endif
#define SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE SDL_VERSION_ATLEAST(2,0,4)
#define SDL_HAS_MOUSE_FOCUS_CLICKTHROUGH SDL_VERSION_ATLEAST(2,0,5)
#define SDL_HAS_VULKAN SDL_VERSION_ATLEAST(2,0,6)
struct ImGui_ImplSDL2_Data
@ -220,6 +222,15 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window)
(void)window;
#endif
// Set SDL hint to receive mouse click events on window focus, otherwise SDL doesn't emit the event.
// Without this, when clicking to gain focus, our widgets wouldn't activate even though they showed as hovered.
// (This is unfortunately a global SDL setting, so enabling it might have a side-effect on your application.
// It is unlikely to make a difference, but if your app absolutely needs to ignore the initial on-focus click:
// you can ignore SDL_MOUSEBUTTONDOWN events coming right after a SDL_WINDOWEVENT_FOCUS_GAINED)
#if SDL_HAS_MOUSE_FOCUS_CLICKTHROUGH
SDL_SetHint(SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, "1");
#endif
return true;
}
@ -284,8 +295,14 @@ static void ImGui_ImplSDL2_UpdateMousePosAndButtons()
bd->MousePressed[0] = bd->MousePressed[1] = bd->MousePressed[2] = false;
#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE && !defined(__EMSCRIPTEN__) && !defined(__ANDROID__) && !(defined(__APPLE__) && TARGET_OS_IOS)
SDL_Window* focused_window = SDL_GetKeyboardFocus();
if (bd->Window == focused_window)
SDL_Window* focused_window = SDL_GetKeyboardFocus(); // Mouse position won't be reported unless window is focused.
#if SDL_HAS_MOUSE_FOCUS_CLICKTHROUGH
SDL_Window* hovered_window = SDL_GetMouseFocus(); // This is better but is only reliably useful with SDL 2.0.5+ and SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH enabled.
SDL_Window* mouse_window = (bd->Window == focused_window || bd->Window == hovered_window) ? bd->Window : NULL;
#else
SDL_Window* mouse_window = (bd->Window == focused_window) ? bd->Window : NULL;
#endif
if (mouse_window != NULL)
{
if (bd->MouseCanUseGlobalState)
{
@ -293,7 +310,7 @@ static void ImGui_ImplSDL2_UpdateMousePosAndButtons()
// The creation of a new windows at runtime and SDL_CaptureMouse both seems to severely mess up with that, so we retrieve that position globally.
// Won't use this workaround on SDL backends that have no global mouse position, like Wayland or RPI
int wx, wy;
SDL_GetWindowPosition(focused_window, &wx, &wy);
SDL_GetWindowPosition(mouse_window, &wx, &wy);
SDL_GetGlobalMouseState(&mx, &my);
mx -= wx;
my -= wy;
@ -306,6 +323,7 @@ static void ImGui_ImplSDL2_UpdateMousePosAndButtons()
bool any_mouse_button_down = ImGui::IsAnyMouseDown();
SDL_CaptureMouse(any_mouse_button_down ? SDL_TRUE : SDL_FALSE);
#else
// SDL 2.0.3 and non-windowed systems
if (SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_INPUT_FOCUS)
io.MousePos = ImVec2((float)mx, (float)my);
#endif