Window: Workaround for a key handling issue

Likely a rare situation, but this workaround should be relatively
safe -- ignore keydown events if they occur less than 10 milliseconds
after the window has received input focus.

IssueID #10

2 files changed, 14 insertions, 0 deletions

diff --git a/src/ui/window.c b/src/ui/window.c
index 1599d372..105dcfb3 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -525,6 +525,7 @@ void init_Window(iWindow *d, iRect rect) {
     d->pendingCursor = NULL;
     d->isDrawFrozen = iTrue;
     d->isMouseInside = iTrue;
+    d->focusGainedAt = 0;
     uint32_t flags = 0;
 #if defined (iPlatformApple)
     SDL_SetHint(SDL_HINT_RENDER_DRIVER, shouldDefaultToMetalRenderer_MacOS() ? "metal" : "opengl");
@@ -668,6 +669,12 @@ static iBool handleWindowEvent_Window_(iWindow *d, const SDL_WindowEvent *ev) {
             d->isMouseInside = iTrue;
             postCommand_App("window.mouse.entered");
             return iTrue;
+        case SDL_WINDOWEVENT_TAKE_FOCUS:
+            SDL_SetWindowInputFocus(d->win);
+            return iTrue;
+        case SDL_WINDOWEVENT_FOCUS_GAINED:
+            d->focusGainedAt = SDL_GetTicks();
+            return iFalse;
         default:
             break;
     }
@@ -699,6 +706,12 @@ iBool processEvent_Window(iWindow *d, const SDL_Event *ev) {
                 postRefresh_App();
                 return iTrue;
             }
+            if (event.type == SDL_KEYDOWN && SDL_GetTicks() - d->focusGainedAt < 10) {
+                /* Suspiciously close to when input focus was received. For example under openbox,
+                   closing xterm with Ctrl+D will cause the keydown event to "spill" over to us.
+                   As a workaround, ignore these events. */
+                return iFalse;
+            }
             /* Map mouse pointer coordinate to our coordinate system. */
             if (event.type == SDL_MOUSEMOTION) {
                 setCursor_Window(d, SDL_SYSTEM_CURSOR_ARROW); /* default cursor */
diff --git a/src/ui/window.h b/src/ui/window.h
index 3ede1578..18df0cf9 100644
--- a/src/ui/window.h
+++ b/src/ui/window.h
@@ -38,6 +38,7 @@ struct Impl_Window {
     iRect         lastRect; /* updated when window is moved/resized */
     iBool         isDrawFrozen; /* avoids premature draws while restoring window state */
     iBool         isMouseInside;
+    uint32_t      focusGainedAt;
     SDL_Renderer *render;
     iWidget *     root;
     float         pixelRatio;