ShowImage: Reset slide show delay if a user interferes

This change resets the delay when the user moves to next/previous image or
page within an image (e.g. TIFF) or deletes an image while a slide show is
running.

Fixes #16321
Change-Id: If0b8f4caef9c6aa4c0ad5bbb01d65bf43c1f831f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2967
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

src/apps/showimage/ShowImageWindow.cpp

@@ -1251,6 +1251,10 @@ ShowImageWindow::_ClosePrompt()
 status_t
 ShowImageWindow::_LoadImage(bool forward)
 {
+	// If the user triggered a _LoadImage while in a slide show,
+	// make sure the new image is shown for the set delay:
+	_ResetSlideShowDelay();
+
 	BMessenger us(this);
 	status_t status = my_app->DefaultCache().RetrieveImage(
 		fNavigator.CurrentRef(), fNavigator.CurrentPage(), &us);
@@ -1513,6 +1517,14 @@ ShowImageWindow::_StopSlideShow()
 }
 
 
+void
+ShowImageWindow::_ResetSlideShowDelay()
+{
+	if (fSlideShowRunner != NULL)
+		fSlideShowRunner->SetInterval(fSlideShowDelay);
+}
+
+
 void
 ShowImageWindow::_UpdateRatingMenu()
 {

src/apps/showimage/ShowImageWindow.h

@@ -101,6 +101,7 @@ private:
 			void				_SetSlideShowDelay(bigtime_t delay);
 			void				_StartSlideShow();
 			void				_StopSlideShow();
+			void				_ResetSlideShowDelay();
 
 			void				_UpdateRatingMenu();