Add function to set backend scale factor

Author: tokyovigilante

include/wpe/view-backend.h

@@ -104,8 +104,8 @@ struct wpe_view_backend_client {
     void (*frame_displayed)(void*);
     void (*activity_state_changed)(void*, uint32_t);
     void* (*get_accessible)(void*);
+    void (*set_device_scale_factor)(void*, float);
     void (*_wpe_reserved0)(void);
-    void (*_wpe_reserved1)(void);
 };
 
 WPE_EXPORT
@@ -132,6 +132,10 @@ WPE_EXPORT
 void*
 wpe_view_backend_dispatch_get_accessible(struct wpe_view_backend* backend);
 
+WPE_EXPORT
+void
+wpe_view_backend_dispatch_set_device_scale_factor(struct wpe_view_backend*, float);
+
 struct wpe_view_backend_input_client {
     void (*handle_keyboard_event)(void*, struct wpe_input_keyboard_event*);
     void (*handle_pointer_event)(void*, struct wpe_input_pointer_event*);

src/view-backend.c

@@ -154,6 +154,13 @@ wpe_view_backend_dispatch_get_accessible(struct wpe_view_backend* backend)
     return NULL;
 }
 
+void
+wpe_view_backend_dispatch_set_device_scale_factor(struct wpe_view_backend* backend, float scale)
+{
+    if (backend->backend_client && backend->backend_client->set_device_scale_factor)
+        backend->backend_client->set_device_scale_factor(backend->backend_client_data, scale);
+}
+
 void
 wpe_view_backend_dispatch_keyboard_event(struct wpe_view_backend* backend, struct wpe_input_keyboard_event* event)
 {