Add sixtyfps::Window::request_redraw()

This allows scheduling a redraw of a Window explicitly. Unfortunately it
comes with a winit caveat :(

Author: tronical

CHANGELOG.md

@@ -29,6 +29,7 @@ as well as the [Rust migration guide for the `sixtyfps` crate](api/sixtyfps-rs/m
 
  - `TextEdit::font-size` and `LineEdit::font-size` have been added to control the size of these widgets.
  - Added `sixtyfps::Window::set_rendering_notifier` to get a callback before and after a new frame is being rendered.
+ - Added `sixtyfps::Window::request_redraw()` to schedule redrawing of the window contents.
 
 ### Fixed
 

api/cpp/cbindgen.rs

@@ -268,6 +268,7 @@ fn gen_corelib(
             "sixtyfps_windowrc_set_component",
             "sixtyfps_windowrc_show_popup",
             "sixtyfps_windowrc_set_rendering_notifier",
+            "sixtyfps_windowrc_request_redraw",
             "sixtyfps_new_path_elements",
             "sixtyfps_new_path_events",
             "sixtyfps_color_brighter",

api/cpp/include/sixtyfps.h

@@ -158,6 +158,8 @@ class WindowRc
         }
     }
 
+    void request_redraw() const { cbindgen_private::sixtyfps_windowrc_request_redraw(&inner); }
+
 private:
     cbindgen_private::WindowRcOpaque inner;
 };
@@ -177,7 +179,8 @@ constexpr inline ItemTreeNode make_dyn_node(std::uintptr_t offset, std::uint32_t
                                                            parent_index } };
 }
 
-inline ItemRef get_item_ref(ComponentRef component, cbindgen_private::Slice<ItemTreeNode> item_tree, int index)
+inline ItemRef get_item_ref(ComponentRef component, cbindgen_private::Slice<ItemTreeNode> item_tree,
+                            int index)
 {
     const auto &item = item_tree.ptr[index].item.item;
     return ItemRef { item.vtable, reinterpret_cast<char *>(component.instance) + item.offset };
@@ -341,6 +344,9 @@ class Window
         return inner.set_rendering_notifier(std::forward<F>(callback));
     }
 
+    /// This function issues a request to the windowing system to redraw the contents of the window.
+    void request_redraw() const { inner.request_redraw(); }
+
     /// \private
     private_api::WindowRc &window_handle() { return inner; }
     /// \private
@@ -429,7 +435,8 @@ inline SharedVector<float> solve_box_layout(const cbindgen_private::BoxLayoutDat
                                             cbindgen_private::Slice<int> repeater_indexes)
 {
     SharedVector<float> result;
-    cbindgen_private::Slice<uint32_t> ri { reinterpret_cast<uint32_t *>(repeater_indexes.ptr), repeater_indexes.len };
+    cbindgen_private::Slice<uint32_t> ri { reinterpret_cast<uint32_t *>(repeater_indexes.ptr),
+                                           repeater_indexes.len };
     cbindgen_private::sixtyfps_solve_box_layout(&data, ri, &result);
     return result;
 }
@@ -467,7 +474,8 @@ inline SharedVector<float> solve_path_layout(const cbindgen_private::PathLayoutD
                                              cbindgen_private::Slice<int> repeater_indexes)
 {
     SharedVector<float> result;
-    cbindgen_private::Slice<uint32_t> ri { reinterpret_cast<uint32_t *>(repeater_indexes.ptr), repeater_indexes.len };
+    cbindgen_private::Slice<uint32_t> ri { reinterpret_cast<uint32_t *>(repeater_indexes.ptr),
+                                           repeater_indexes.len };
     cbindgen_private::sixtyfps_solve_path_layout(&data, ri, &result);
     return result;
 }
@@ -490,7 +498,8 @@ struct AbstractRepeaterView
 using ModelPeer = std::weak_ptr<AbstractRepeaterView>;
 
 template<typename M>
-auto access_array_index(const M &model, int index) {
+auto access_array_index(const M &model, int index)
+{
     model->track_row_data_changes(index);
     if (const auto v = model->row_data(index)) {
         return *v;

internal/core/api.rs

@@ -119,6 +119,18 @@ impl Window {
     ) -> std::result::Result<(), SetRenderingNotifierError> {
         self.0.set_rendering_notifier(Box::new(callback))
     }
+
+    /// This function issues a request to the windowing system to redraw the contents of the window.
+    pub fn request_redraw(&self) {
+        self.0.request_redraw();
+
+        // When this function is called by the user, we want it to translate to a requestAnimationFrame()
+        // on the web. If called through the rendering notifier (so from within the event loop processing),
+        // unfortunately winit will only do that if set the control flow to Poll. This hack achieves that.
+        #[cfg(target_arch = "wasm32")]
+        crate::animations::CURRENT_ANIMATION_DRIVER
+            .with(|driver| driver.set_has_active_animations());
+    }
 }
 
 impl crate::window::WindowHandleAccess for Window {

internal/core/window.rs

@@ -729,4 +729,11 @@ pub mod ffi {
             }
         }
     }
+
+    /// This function issues a request to the windowing system to redraw the contents of the window.
+    #[no_mangle]
+    pub unsafe extern "C" fn sixtyfps_windowrc_request_redraw(handle: *const WindowRcOpaque) {
+        let window = &*(handle as *const WindowRc);
+        window.request_redraw();
+    }
 }