text cursor blink in TextEdit

crates/egui/src/input_state.rs

@@ -416,6 +416,11 @@ impl InputState {
             .count()
     }
 
+    /// Tells whether there is a key currently being pressed down.
+    pub fn has_key_down(&self) -> bool {
+        !self.keys_down.is_empty()
+    }
+
     /// Is the given key currently held down?
     pub fn key_down(&self, desired_key: Key) -> bool {
         self.keys_down.contains(&desired_key)

crates/egui/src/style.rs

@@ -647,6 +647,27 @@ pub struct Interaction {
     pub multi_widget_text_select: bool,
 }
 
+/// Text Cursor Style
+#[derive(Clone, Default, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "serde", serde(default))]
+pub struct TextCursorStyle {
+    /// show where the text cursor would be if you clicked
+    pub preview: bool,
+
+    /// set the text cursor to blink
+    pub blink: bool,
+
+    /// set the text cursor on duration
+    pub on_duration: f64,
+
+    /// set the text cursor off duration
+    pub off_duration: f64,
+
+    /// This is the time when the key was last pressed.
+    pub last_edit_time: f64,
+}
+
 /// Controls the visual style (colors etc) of egui.
 ///
 /// You can change the visuals of a [`Ui`] with [`Ui::visuals_mut`]
@@ -725,8 +746,8 @@ pub struct Visuals {
     /// The color and width of the text cursor
     pub text_cursor: Stroke,
 
-    /// show where the text cursor would be if you clicked
-    pub text_cursor_preview: bool,
+    /// Text Cursor Style for blink
+    pub text_cursor_style: TextCursorStyle,
 
     /// Allow child widgets to be just on the border and still have a stroke with some thickness
     pub clip_rect_margin: f32,
@@ -1095,7 +1116,13 @@ impl Visuals {
             resize_corner_size: 12.0,
 
             text_cursor: Stroke::new(2.0, Color32::from_rgb(192, 222, 255)),
-            text_cursor_preview: false,
+            text_cursor_style: TextCursorStyle {
+                preview: false,
+                blink: true,
+                on_duration: 1.0,
+                off_duration: 0.3,
+                last_edit_time: Default::default(),
+            },
 
             clip_rect_margin: 3.0, // should be at least half the size of the widest frame stroke + max WidgetVisuals::expansion
             button_frame: true,
@@ -1581,10 +1608,10 @@ impl Interaction {
 impl Widgets {
     pub fn ui(&mut self, ui: &mut crate::Ui) {
         let Self {
-            active,
-            hovered,
-            inactive,
             noninteractive,
+            inactive,
+            hovered,
+            active,
             open,
         } = self;
 
@@ -1738,7 +1765,7 @@ impl Visuals {
 
             resize_corner_size,
             text_cursor,
-            text_cursor_preview,
+            text_cursor_style,
             clip_rect_margin,
             button_frame,
             collapsing_header_frame,
@@ -1843,7 +1870,19 @@ impl Visuals {
 
         ui.collapsing("Misc", |ui| {
             ui.add(Slider::new(resize_corner_size, 0.0..=20.0).text("resize_corner_size"));
-            ui.checkbox(text_cursor_preview, "Preview text cursor on hover");
+            ui.checkbox(
+                &mut text_cursor_style.preview,
+                "Preview text cursor on hover",
+            );
+            ui.checkbox(&mut text_cursor_style.blink, "text cursor to blink");
+            ui.add(
+                Slider::new(&mut text_cursor_style.on_duration, 0.0..=2.0)
+                    .text("text cursor on duration"),
+            );
+            ui.add(
+                Slider::new(&mut text_cursor_style.off_duration, 0.0..=2.0)
+                    .text("text cursor off duration"),
+            );
             ui.add(Slider::new(clip_rect_margin, 0.0..=20.0).text("clip_rect_margin"));
 
             ui.checkbox(button_frame, "Button has a frame");

crates/egui/src/text_selection/visuals.rs

@@ -73,3 +73,46 @@ pub fn paint_cursor(painter: &Painter, visuals: &Visuals, cursor_rect: Rect) {
         );
     }
 }
+
+/// Paint text cursor.
+pub fn paint_text_cursor(
+    ui: &mut Ui,
+    painter: &Painter,
+    primary_cursor_rect: Rect,
+    blink_pause: bool,
+) {
+    let i_time = ui.input(|i| i.time);
+    let blink_mode = ui.visuals().text_cursor_style.blink;
+    let is_blink_mode = blink_mode && !blink_pause;
+
+    let on_duration = ui.visuals().text_cursor_style.on_duration;
+    let off_duration = ui.visuals().text_cursor_style.off_duration;
+    let total_duration = on_duration + off_duration;
+
+    let mut is_cursor_visible = true;
+
+    if is_blink_mode {
+        // Check if the text cursor is on/off based on the time
+        is_cursor_visible = (i_time % total_duration) < on_duration;
+    }
+
+    // Keep the text cursor visible for some time.
+    if i_time < ui.visuals().text_cursor_style.last_edit_time + 3.0 {
+        is_cursor_visible = true;
+    }
+
+    if is_cursor_visible {
+        paint_cursor(painter, ui.visuals(), primary_cursor_rect);
+    }
+
+    if blink_mode {
+        if is_cursor_visible {
+            ui.ctx()
+                .request_repaint_after(std::time::Duration::from_secs_f64(on_duration));
+        }
+        if !is_cursor_visible {
+            ui.ctx()
+                .request_repaint_after(std::time::Duration::from_secs_f64(off_duration));
+        }
+    }
+}

crates/egui/src/widgets/text_edit/builder.rs

@@ -511,6 +511,7 @@ impl<'t> TextEdit<'t> {
             }
         });
         let mut state = TextEditState::load(ui.ctx(), id).unwrap_or_default();
+        let save_ccursor_range = state.cursor.char_range();
 
         // On touch screens (e.g. mobile in `eframe` web), should
         // dragging select text, or scroll the enclosing [`ScrollArea`] (if any)?
@@ -544,11 +545,11 @@ impl<'t> TextEdit<'t> {
                 let cursor_at_pointer =
                     galley.cursor_from_pos(pointer_pos - rect.min + singleline_offset);
 
-                if ui.visuals().text_cursor_preview
+                if ui.visuals().text_cursor_style.preview
                     && response.hovered()
                     && ui.input(|i| i.pointer.is_moving())
                 {
-                    // preview:
+                    // text cursor preview:
                     let cursor_rect =
                         cursor_rect(rect.min, &galley, &cursor_at_pointer, row_height);
                     paint_cursor(&painter, ui.visuals(), cursor_rect);
@@ -684,7 +685,20 @@ impl<'t> TextEdit<'t> {
                     }
 
                     if text.is_mutable() {
-                        paint_cursor(&painter, ui.visuals(), primary_cursor_rect);
+                        let has_key_down = ui.ctx().input(|i| i.has_key_down());
+                        if has_key_down {
+                            ui.visuals_mut().text_cursor_style.last_edit_time =
+                                ui.ctx().input(|i| i.time);
+                        }
+                        let blink_pause =
+                            (save_ccursor_range != state.cursor.char_range()) || has_key_down;
+
+                        text_selection::visuals::paint_text_cursor(
+                            ui,
+                            &painter,
+                            primary_cursor_rect,
+                            blink_pause,
+                        );
 
                         if interactive {
                             // For IME, so only set it when text is editable and visible!