win32: support taskbar button progress indicator

This adds support for the progress indicator taskbar extension
that was introduced with Windows 7 and Windows Server 2008 R2.

I don’t like this solution because it keeps its own state and
introduces another VOCTRL, but I couldn’t come up with anything
less messy.

closes #2399

1 files changed, 7 insertions, 0 deletions

diff --git a/video/out/vo.h b/video/out/vo.h
index 30948e149b..3a8231a295 100644
--- a/video/out/vo.h
+++ b/video/out/vo.h
@@ -76,6 +76,7 @@ enum mp_voctrl {
     VOCTRL_ALL_WORKSPACES,
 
     VOCTRL_UPDATE_WINDOW_TITLE,         // char*
+    VOCTRL_UPDATE_PLAYBACK_STATE,       // struct voctrl_playback_state*
 
     VOCTRL_SET_CURSOR_VISIBILITY,       // bool*
 
@@ -130,6 +131,12 @@ struct voctrl_get_equalizer_args {
 #define VO_NOTAVAIL     -2
 #define VO_NOTIMPL      -3
 
+// VOCTRL_UPDATE_PLAYBACK_STATE
+struct voctrl_playback_state {
+    bool paused;
+    int percent_pos;
+};
+
 enum {
     // VO does handle mp_image_params.rotate in 90 degree steps
     VO_CAP_ROTATE90     = 1 << 0,