Make repaint by regions

src/shell.rs

@@ -145,7 +145,6 @@ impl State {
             _ => self.drawing_area.queue_draw(),
         }
     }
-
 }
 
 pub struct UiState {
@@ -347,28 +346,16 @@ fn gtk_scroll_event(state: &mut State, ev: &EventScroll) -> Inhibit {
 
     match ev.as_ref().direction {
         ScrollDirection::Right => {
-            mouse_input(state,
-                        "ScrollWheelRight",
-                        ev.get_state(),
-                        ev.get_position())
+            mouse_input(state, "ScrollWheelRight", ev.get_state(), ev.get_position())
         }
         ScrollDirection::Left => {
-            mouse_input(state,
-                        "ScrollWheelLeft",
-                        ev.get_state(),
-                        ev.get_position())
+            mouse_input(state, "ScrollWheelLeft", ev.get_state(), ev.get_position())
         }
         ScrollDirection::Up => {
-            mouse_input(state,
-                        "ScrollWheelUp",
-                        ev.get_state(),
-                        ev.get_position())
+            mouse_input(state, "ScrollWheelUp", ev.get_state(), ev.get_position())
         }
         ScrollDirection::Down => {
-            mouse_input(state,
-                        "ScrollWheelDown",
-                        ev.get_state(),
-                        ev.get_position())
+            mouse_input(state, "ScrollWheelDown", ev.get_state(), ev.get_position())
         }
         _ => (),
     }
@@ -383,18 +370,12 @@ fn gtk_button_press(shell: &mut State, ui_state: &mut UiState, ev: &EventButton)
     if shell.mouse_enabled {
         ui_state.mouse_pressed = true;
 
-        mouse_input(shell,
-                    "LeftMouse",
-                    ev.get_state(),
-                    ev.get_position());
+        mouse_input(shell, "LeftMouse", ev.get_state(), ev.get_position());
     }
     Inhibit(false)
 }
 
-fn mouse_input(shell: &mut State,
-               input: &str,
-               state: ModifierType,
-               position: (f64, f64)) {
+fn mouse_input(shell: &mut State, input: &str, state: ModifierType, position: (f64, f64)) {
     if let Some(line_height) = shell.line_height {
         if let Some(char_width) = shell.char_width {
 
@@ -416,10 +397,7 @@ fn gtk_button_release(ui_state: &mut UiState) -> Inhibit {
 
 fn gtk_motion_notify(shell: &mut State, ui_state: &mut UiState, ev: &EventMotion) -> Inhibit {
     if shell.mouse_enabled && ui_state.mouse_pressed {
-        mouse_input(shell,
-                    "LeftDrag",
-                    ev.get_state(),
-                    ev.get_position());
+        mouse_input(shell, "LeftDrag", ev.get_state(), ev.get_position());
     }
     Inhibit(false)
 }
@@ -459,7 +437,11 @@ fn draw_joined_rect(state: &State,
 }
 
 #[inline]
-fn get_model_clip(state: &State, line_height: f64, char_width: f64, clip: (f64, f64, f64, f64)) -> ModelRect {
+fn get_model_clip(state: &State,
+                  line_height: f64,
+                  char_width: f64,
+                  clip: (f64, f64, f64, f64))
+                  -> ModelRect {
     let mut model_clip =
         ModelRect::from_area(line_height, char_width, clip.0, clip.1, clip.2, clip.3);
     // in some cases symbols from previous row affect next row
@@ -472,7 +454,11 @@ fn get_model_clip(state: &State, line_height: f64, char_width: f64, clip: (f64,
 }
 
 #[inline]
-fn draw_backgound(state: &State, ctx: &cairo::Context, line_height: f64, char_width: f64, model_clip: &ModelRect) {
+fn draw_backgound(state: &State,
+                  ctx: &cairo::Context,
+                  line_height: f64,
+                  char_width: f64,
+                  model_clip: &ModelRect) {
     let line_x = model_clip.left as f64 * char_width;
     let mut line_y: f64 = model_clip.top as f64 * line_height;
 
@@ -515,24 +501,30 @@ fn draw_backgound(state: &State, ctx: &cairo::Context, line_height: f64, char_wi
 }
 
 fn draw(state: &State, ctx: &cairo::Context) {
-    ctx.set_source_rgb(state.bg_color.0, state.bg_color.1, state.bg_color.2);
-    ctx.paint();
+    let layout = pc::create_layout(ctx);
+    let mut desc = state.create_pango_font();
+    let mut buf = String::with_capacity(4);
+
+    let (row, col) = state.model.get_cursor();
 
     let line_height = state.line_height.unwrap();
     let char_width = state.char_width.unwrap();
 
-    let model_clip = get_model_clip(state, line_height, char_width, ctx.clip_extents());
+    ctx.set_source_rgb(state.bg_color.0, state.bg_color.1, state.bg_color.2);
+    ctx.paint();
+
+    let clip_rects = &ctx.copy_clip_rectangle_list().rectangles;
+    for clip_idx in 0..clip_rects.len() {
+        let clip = clip_rects.get(clip_idx).unwrap();
+
+        let model_clip = get_model_clip(state,
+                                        line_height,
+                                        char_width,
+                                        (clip.x, clip.y, clip.x + clip.width, clip.y + clip.height));
 
         let line_x = model_clip.left as f64 * char_width;
         let mut line_y: f64 = model_clip.top as f64 * line_height;
 
-    let (row, col) = state.model.get_cursor();
-    let mut buf = String::with_capacity(4);
-
-
-    let layout = pc::create_layout(ctx);
-    let mut desc = state.create_pango_font();
-
         draw_backgound(state, ctx, line_height, char_width, &model_clip);
 
         for (line_idx, line) in state.model.clip_model(&model_clip) {
@@ -620,6 +612,7 @@ fn draw(state: &State, ctx: &cairo::Context) {
             line_y += line_height;
         }
     }
+}
 
 #[inline]
 fn update_font_description(desc: &mut FontDescription, attrs: &Attrs) {