Basic rich text

CHANGELOG.md

@@ -43,6 +43,7 @@ You can find its changes [documented below](#060---2020-06-01).
 - CONFIGURE_WINDOW command to allow reconfiguration of an existing window. ([#1235] by [@rjwittams])
 - `RawLabel` widget displays text `Data`. ([#1252] by [@cmyr])
 - 'Tabs' widget allowing static and dynamic tabbed layouts. ([#1160] by [@rjwittams])
+- `RichText` and `Attribute` types for creating rich text ([#1255] by [@cmyr])
 
 ### Changed
 
@@ -476,6 +477,7 @@ Last release without a changelog :(
 [#1245]: https://github.com/linebender/druid/pull/1245
 [#1251]: https://github.com/linebender/druid/pull/1251
 [#1252]: https://github.com/linebender/druid/pull/1252
+[#1255]: https://github.com/linebender/druid/pull/1255
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.6.0...master
 [0.6.0]: https://github.com/linebender/druid/compare/v0.5.0...v0.6.0

druid/examples/custom_widget.rs

@@ -18,7 +18,7 @@ use druid::kurbo::BezPath;
 use druid::piet::{FontFamily, ImageFormat, InterpolationMode};
 use druid::widget::prelude::*;
 use druid::{
-    Affine, AppLauncher, Color, FontDescriptor, LocalizedString, Point, Rect, TextLayout,
+    Affine, AppLauncher, ArcStr, Color, FontDescriptor, LocalizedString, Point, Rect, TextLayout,
     WindowDesc,
 };
 
@@ -86,7 +86,7 @@ impl Widget<String> for CustomWidget {
 
         // Text is easy; in real use TextLayout should be stored in the widget
         // and reused.
-        let mut layout = TextLayout::new(data.as_str());
+        let mut layout = TextLayout::<ArcStr>::from_text(data.to_owned());
         layout.set_font(FontDescriptor::new(FontFamily::SERIF).with_size(24.0));
         layout.set_text_color(fill_color);
         layout.rebuild_if_needed(ctx.text(), env);

druid/examples/text.rs

@@ -14,10 +14,13 @@
 
 //! An example of various text layout features.
 
-use druid::widget::{Controller, Flex, Label, LineBreaking, RadioGroup, Scroll};
+use druid::piet::{PietTextLayoutBuilder, TextStorage as PietTextStorage};
+use druid::text::{Attribute, RichText, TextStorage};
+use druid::widget::prelude::*;
+use druid::widget::{Controller, Flex, Label, LineBreaking, RadioGroup, RawLabel, Scroll};
 use druid::{
-    AppLauncher, Color, Data, Env, Lens, LocalizedString, TextAlignment, UpdateCtx, Widget,
-    WidgetExt, WindowDesc,
+    AppLauncher, Color, Data, FontFamily, FontStyle, FontWeight, Lens, LocalizedString,
+    TextAlignment, Widget, WidgetExt, WindowDesc,
 };
 
 const WINDOW_TITLE: LocalizedString<AppState> = LocalizedString::new("Text Options");
@@ -29,18 +32,34 @@ const SPACER_SIZE: f64 = 8.0;
 
 #[derive(Clone, Data, Lens)]
 struct AppState {
+    text: RichText,
     line_break_mode: LineBreaking,
     alignment: TextAlignment,
 }
 
-/// A controller that sets properties on a label.
+//NOTE: we implement these traits for our base data (instead of just lensing
+//into the RichText object, for the label) so that our label controller can
+//have access to the other fields.
+impl PietTextStorage for AppState {
+    fn as_str(&self) -> &str {
+        self.text.as_str()
+    }
+}
+
+impl TextStorage for AppState {
+    fn add_attributes(&self, builder: PietTextLayoutBuilder, env: &Env) -> PietTextLayoutBuilder {
+        self.text.add_attributes(builder, env)
+    }
+}
+
+/// A controller that updates label properties as required.
 struct LabelController;
 
-impl Controller<AppState, Label<AppState>> for LabelController {
+impl Controller<AppState, RawLabel<AppState>> for LabelController {
     #[allow(clippy::float_cmp)]
     fn update(
         &mut self,
-        child: &mut Label<AppState>,
+        child: &mut RawLabel<AppState>,
         ctx: &mut UpdateCtx,
         old_data: &AppState,
         data: &AppState,
@@ -52,6 +71,7 @@ impl Controller<AppState, Label<AppState>> for LabelController {
         }
         if old_data.alignment != data.alignment {
             child.set_text_alignment(data.alignment);
+            ctx.request_layout();
         }
         child.update(ctx, old_data, data, env);
     }
@@ -63,10 +83,19 @@ pub fn main() {
         .title(WINDOW_TITLE)
         .window_size((400.0, 600.0));
 
+    let text = RichText::new(TEXT.into())
+        .with_attribute(0..9, Attribute::text_color(Color::rgb(1.0, 0.2, 0.1)))
+        .with_attribute(0..9, Attribute::size(24.0))
+        .with_attribute(0..9, Attribute::font_family(FontFamily::SERIF))
+        .with_attribute(194..239, Attribute::weight(FontWeight::BOLD))
+        .with_attribute(764.., Attribute::size(12.0))
+        .with_attribute(764.., Attribute::style(FontStyle::Italic));
+
     // create the initial app state
     let initial_state = AppState {
         line_break_mode: LineBreaking::Clip,
         alignment: Default::default(),
+        text,
     };
 
     // start the application
@@ -78,7 +107,7 @@ pub fn main() {
 
 fn build_root_widget() -> impl Widget<AppState> {
     let label = Scroll::new(
-        Label::new(TEXT)
+        RawLabel::new()
             .with_text_color(Color::BLACK)
             .controller(LabelController)
             .background(Color::WHITE)

druid/src/core.rs

@@ -21,9 +21,9 @@ use crate::contexts::ContextState;
 use crate::kurbo::{Affine, Insets, Point, Rect, Shape, Size, Vec2};
 use crate::util::ExtendDrain;
 use crate::{
-    BoxConstraints, Color, Command, Data, Env, Event, EventCtx, InternalEvent, InternalLifeCycle,
-    LayoutCtx, LifeCycle, LifeCycleCtx, PaintCtx, Region, RenderContext, Target, TextLayout,
-    TimerToken, UpdateCtx, Widget, WidgetId,
+    ArcStr, BoxConstraints, Color, Command, Data, Env, Event, EventCtx, InternalEvent,
+    InternalLifeCycle, LayoutCtx, LifeCycle, LifeCycleCtx, PaintCtx, Region, RenderContext, Target,
+    TextLayout, TimerToken, UpdateCtx, Widget, WidgetId,
 };
 
 /// Our queue type
@@ -50,7 +50,7 @@ pub struct WidgetPod<T, W> {
     env: Option<Env>,
     inner: W,
     // stashed layout so we don't recompute this when debugging
-    debug_widget_text: TextLayout,
+    debug_widget_text: TextLayout<ArcStr>,
 }
 
 /// Generic state for all widgets in the hierarchy.
@@ -144,7 +144,7 @@ impl<T, W: Widget<T>> WidgetPod<T, W> {
             old_data: None,
             env: None,
             inner,
-            debug_widget_text: TextLayout::new(""),
+            debug_widget_text: TextLayout::new(),
         }
     }
 
@@ -433,7 +433,7 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                 Color::BLACK
             };
             let id_string = id.to_raw().to_string();
-            self.debug_widget_text.set_text(id_string);
+            self.debug_widget_text.set_text(id_string.into());
             self.debug_widget_text.set_text_size(10.0);
             self.debug_widget_text.set_text_color(text_color);
             self.debug_widget_text.rebuild_if_needed(ctx.text(), env);

druid/src/data.rs

@@ -119,12 +119,6 @@ pub trait Data: Clone + 'static {
     //// ANCHOR_END: same_fn
 }
 
-/// A reference counted string slice.
-///
-/// This is a data-friendly way to represent strings in druid. Unlike `String`
-/// it cannot be mutated, but unlike `String` it can be cheaply cloned.
-pub type ArcStr = Arc<str>;
-
 /// An impl of `Data` suitable for simple types.
 ///
 /// The `same` method is implemented with equality, so the type should

druid/src/lib.rs

@@ -191,15 +191,15 @@ pub use app_delegate::{AppDelegate, DelegateCtx};
 pub use box_constraints::BoxConstraints;
 pub use command::{sys as commands, Command, Selector, SingleUse, Target};
 pub use contexts::{EventCtx, LayoutCtx, LifeCycleCtx, PaintCtx, UpdateCtx};
-pub use data::{ArcStr, Data};
+pub use data::Data;
 pub use env::{Env, Key, KeyOrValue, Value, ValueType};
 pub use event::{Event, InternalEvent, InternalLifeCycle, LifeCycle};
 pub use ext_event::{ExtEventError, ExtEventSink};
 pub use lens::{Lens, LensExt};
 pub use localization::LocalizedString;
 pub use menu::{sys as platform_menus, ContextMenu, MenuDesc, MenuItem};
 pub use mouse::MouseEvent;
-pub use text::{FontDescriptor, TextLayout};
+pub use text::{ArcStr, FontDescriptor, TextLayout};
 pub use widget::{Widget, WidgetExt, WidgetId};
 pub use win_handler::DruidHandler;
 pub use window::{Window, WindowId};