w32_common: implement VOCTRL_BEGIN_DRAGGING

This allows begin-vo-dragging command to initialize a vo dragging request
for win32. Also set dragging to release all keys like for other platforms.
The hard-coded left mouse button down trigger is scheduled to be removed
in a later commit.

1 files changed, 27 insertions, 18 deletions

diff --git a/video/out/w32_common.c b/video/out/w32_common.c
index cf807c0136..49a15b4a78 100644
--- a/video/out/w32_common.c
+++ b/video/out/w32_common.c
@@ -472,29 +472,35 @@ static bool handle_char(struct vo_w32_state *w32, WPARAM wc, bool decode)
     return true;
 }
 
+static void begin_dragging(struct vo_w32_state *w32)
+{
+    if (mp_input_test_dragging(w32->input_ctx, w32->mouse_x, w32->mouse_y))
+        return;
+    // Window dragging hack
+    ReleaseCapture();
+    // The dragging model loop is entered at SendMessage() here.
+    // Unfortunately, the w32->current_fs value is stale because the
+    // input is handled in a different thread, and we cannot wait for
+    // an up-to-date value before entering the model loop if dragging
+    // needs to be kept resonsive.
+    // Workaround this by intercepting the loop in the WM_MOVING message,
+    // where the up-to-date value is available.
+    SystemParametersInfoW(SPI_GETWINARRANGING, 0, &w32->win_arranging, 0);
+    w32->dragging = true;
+    SendMessage(w32->window, WM_NCLBUTTONDOWN, HTCAPTION, 0);
+    w32->dragging = false;
+    SystemParametersInfoW(SPI_SETWINARRANGING, w32->win_arranging, 0, 0);
+
+    mp_input_put_key(w32->input_ctx, MP_INPUT_RELEASE_ALL);
+}
+
 static bool handle_mouse_down(struct vo_w32_state *w32, int btn, int x, int y)
 {
     btn |= mod_state(w32);
     mp_input_put_key(w32->input_ctx, btn | MP_KEY_STATE_DOWN);
 
-    if (btn == MP_MBTN_LEFT && !mp_input_test_dragging(w32->input_ctx, x, y)) {
-        // Window dragging hack
-        ReleaseCapture();
-        // The dragging model loop is entered at SendMessage() here.
-        // Unfortunately, the w32->current_fs value is stale because the
-        // input is handled in a different thread, and we cannot wait for
-        // an up-to-date value before entering the model loop if dragging
-        // needs to be kept resonsive.
-        // Workaround this by intercepting the loop in the WM_MOVING message,
-        // where the up-to-date value is available.
-        SystemParametersInfoW(SPI_GETWINARRANGING, 0, &w32->win_arranging, 0);
-        w32->dragging = true;
-        SendMessage(w32->window, WM_NCLBUTTONDOWN, HTCAPTION, 0);
-        w32->dragging = false;
-        SystemParametersInfoW(SPI_SETWINARRANGING, w32->win_arranging, 0, 0);
-
-        mp_input_put_key(w32->input_ctx, MP_MBTN_LEFT | MP_KEY_STATE_UP);
-
+    if (btn == MP_MBTN_LEFT) {
+        begin_dragging(w32);
         // Indicate the message was handled, so DefWindowProc won't be called
         return true;
     }
@@ -2164,6 +2170,9 @@ static int gui_thread_control(struct vo_w32_state *w32, int request, void *arg)
     case VOCTRL_GET_FOCUSED:
         *(bool *)arg = w32->focused;
         return VO_TRUE;
+    case VOCTRL_BEGIN_DRAGGING:
+        begin_dragging(w32);
+        return VO_TRUE;
     }
     return VO_NOTIMPL;
 }