Add widget `ImageButton`

CHANGELOG.md

@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Added ⭐
 
+* `ImageButton` - `ui.add(ImageButton::new(...))`
 * `ui.vertical_centered` and `ui.vertical_centered_justified`
 
 ### Changed 🔧

egui/src/style.rs

@@ -159,7 +159,7 @@ impl Visuals {
 }
 
 /// Selected text, selected elements etc
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub struct Selection {
     pub bg_fill: Srgba,

egui/src/widgets/button.rs

@@ -0,0 +1,93 @@
+use crate::*;
+
+#[derive(Clone, Debug)]
+pub struct ImageButton {
+    image: widgets::Image,
+    sense: Sense,
+    frame: bool,
+    selected: bool,
+}
+
+impl ImageButton {
+    pub fn new(texture_id: TextureId, desired_size: impl Into<Vec2>) -> Self {
+        Self {
+            image: widgets::Image::new(texture_id, desired_size),
+            sense: Sense::click(),
+            frame: true,
+            selected: false,
+        }
+    }
+
+    /// Select UV range. Default is (0,0) in top-left, (1,1) bottom right.
+    pub fn uv(mut self, uv: impl Into<Rect>) -> Self {
+        self.image = self.image.uv(uv);
+        self
+    }
+
+    /// Multiply image color with this. Default is WHITE (no tint).
+    pub fn tint(mut self, tint: impl Into<Srgba>) -> Self {
+        self.image = self.image.tint(tint);
+        self
+    }
+
+    /// If `true`, mark this button as "selected".
+    pub fn selected(mut self, selected: bool) -> Self {
+        self.selected = selected;
+        self
+    }
+
+    /// Turn off the frame
+    pub fn frame(mut self, frame: bool) -> Self {
+        self.frame = frame;
+        self
+    }
+
+    /// By default, buttons senses clicks.
+    /// Change this to a drag-button with `Sense::drag()`.
+    pub fn sense(mut self, sense: Sense) -> Self {
+        self.sense = sense;
+        self
+    }
+}
+
+impl Widget for ImageButton {
+    fn ui(self, ui: &mut Ui) -> Response {
+        let Self {
+            image,
+            sense,
+            frame,
+            selected,
+        } = self;
+
+        let button_padding = ui.style().spacing.button_padding;
+        let desired_size = image.desired_size() + 2.0 * button_padding;
+        let rect = ui.allocate_space(desired_size);
+        let id = ui.make_position_id();
+        let response = ui.interact(rect, id, sense);
+
+        if ui.clip_rect().intersects(rect) {
+            let visuals = ui.style().interact(&response);
+
+            if selected {
+                let selection = ui.style().visuals.selection;
+                ui.painter()
+                    .rect(response.rect, 0.0, selection.bg_fill, selection.stroke);
+            } else if frame {
+                ui.painter().rect(
+                    response.rect,
+                    visuals.corner_radius,
+                    visuals.bg_fill,
+                    visuals.bg_stroke,
+                );
+            }
+
+            let image_rect = ui.layout().align_size_within_rect(
+                image.desired_size(),
+                response.rect.shrink2(button_padding),
+            );
+            image.paint_at(ui, image_rect);
+        }
+
+        response
+    }
+}

egui/src/widgets/image.rs

@@ -39,29 +39,40 @@ impl Image {
     }
 }
 
-impl Widget for Image {
-    fn ui(self, ui: &mut Ui) -> Response {
+impl Image {
+    pub fn desired_size(&self) -> Vec2 {
+        self.desired_size
+    }
+
+    pub fn paint_at(&self, ui: &mut Ui, rect: Rect) {
         use paint::*;
         let Self {
             texture_id,
             uv,
-            desired_size,
+            desired_size: _,
             bg_fill,
             tint,
         } = self;
-        let rect = ui.allocate_space(desired_size);
-        if bg_fill != Default::default() {
+
+        if *bg_fill != Default::default() {
             let mut triangles = Triangles::default();
-            triangles.add_colored_rect(rect, bg_fill);
+            triangles.add_colored_rect(rect, *bg_fill);
             ui.painter().add(PaintCmd::triangles(triangles));
         }
+
         {
             // TODO: builder pattern for Triangles
-            let mut triangles = Triangles::with_texture(texture_id);
-            triangles.add_rect_with_uv(rect, uv, tint);
+            let mut triangles = Triangles::with_texture(*texture_id);
+            triangles.add_rect_with_uv(rect, *uv, *tint);
             ui.painter().add(PaintCmd::triangles(triangles));
         }
+    }
+}
 
+impl Widget for Image {
+    fn ui(self, ui: &mut Ui) -> Response {
+        let rect = ui.allocate_space(self.desired_size);
+        self.paint_at(ui, rect);
         ui.interact_hover(rect)
     }
 }

egui/src/widgets/mod.rs

@@ -8,13 +8,14 @@
 
 use crate::*;
 
+mod button;
 pub mod color_picker;
 mod drag_value;
 mod image;
 mod slider;
 pub(crate) mod text_edit;
 
-pub use {drag_value::DragValue, image::Image, slider::*, text_edit::*};
+pub use {button::*, drag_value::DragValue, image::Image, slider::*, text_edit::*};
 
 use paint::*;
 
@@ -380,12 +381,6 @@ impl Widget for Button {
             small,
             frame,
         } = self;
-
-        let mut button_padding = ui.style().spacing.button_padding;
-        if small {
-            button_padding.y = 0.0;
-        }
-
         let font = &ui.fonts()[text_style];
 
         let single_line = ui.layout().is_horizontal();
@@ -395,10 +390,16 @@ impl Widget for Button {
             font.layout_multiline(text, ui.available_width())
         };
 
+        let mut button_padding = ui.style().spacing.button_padding;
+        if small {
+            button_padding.y = 0.0;
+        }
+
         let mut desired_size = galley.size + 2.0 * button_padding;
         if !small {
             desired_size.y = desired_size.y.at_least(ui.style().spacing.interact_size.y);
         }
+
         let rect = ui.allocate_space(desired_size);
 
         let id = ui.make_position_id();