DisabledIf widget

CHANGELOG.md

@@ -675,6 +675,7 @@ Last release without a changelog :(
 [#1691]: https://github.com/linebender/druid/pull/1691
 [#1693]: https://github.com/linebender/druid/pull/1693
 [#1695]: https://github.com/linebender/druid/pull/1695
+[#1696]: https://github.com/linebender/druid/pull/1696
 [#1698]: https://github.com/linebender/druid/pull/1698
 [#1702]: https://github.com/linebender/druid/pull/1702
 

druid/examples/disabled.rs

@@ -1,4 +1,25 @@
-use druid::widget::{Checkbox, CrossAxisAlignment, Flex, Label, Slider, Stepper, Switch, TextBox};
+// Copyright 2020 The Druid Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! An example showing the effect of the disabled state on focus-chain and the widgets.
+//! When the disabled checkbox is clicked only the widgets not marked as disabled should
+//! respond. Pressing Tab should only focus widgets not marked as disabled. If a widget
+//! is focused while getting disabled it should resign the focus.
+
+use druid::widget::{
+    Button, Checkbox, CrossAxisAlignment, Flex, Label, Slider, Stepper, Switch, TextBox,
+};
 use druid::{AppLauncher, Data, Lens, LocalizedString, UnitPoint, Widget, WidgetExt, WindowDesc};
 
 #[derive(Clone, Data, Lens)]
@@ -69,6 +90,25 @@ fn main_widget() -> impl Widget<AppData> {
                 .disabled_if(|data, _| data.disabled),
         ))
         .with_default_spacer()
+        .with_child(
+            Flex::row()
+                .with_child(
+                    Button::new("-")
+                        .on_click(|_, data: &mut f64, _| *data -= 1.0)
+                        .disabled_if(|data, _| *data < 1.0),
+                )
+                .with_default_spacer()
+                .with_child(Label::dynamic(|data: &f64, _| data.to_string()))
+                .with_default_spacer()
+                .with_child(
+                    Button::new("+")
+                        .on_click(|_, data: &mut f64, _| *data += 1.0)
+                        .disabled_if(|data, _| *data > 9.0),
+                )
+                .lens(AppData::value)
+                .disabled_if(|data: &AppData, _| data.disabled),
+        )
+        .with_default_spacer()
         .with_default_spacer()
         .with_default_spacer()
         .with_child(Checkbox::new("disabled").lens(AppData::disabled))

druid/src/widget/disable_if.rs

@@ -1,17 +1,38 @@
+// Copyright 2020 The Druid Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 use crate::{
     BoxConstraints, Data, Env, Event, EventCtx, LayoutCtx, LifeCycle, LifeCycleCtx, PaintCtx,
     Point, Size, UpdateCtx, Widget, WidgetPod,
 };
 
 /// A widget wrapper which disables the inner widget if the provided closure return true.
+///
+/// See [`is_disabled`] or [`set_disabled`] for more info about disabled state.
+///
+/// [`is_disabled`]: crate::EventCtx::is_disabled
+/// [`set_disabled`]: crate::EventCtx::set_disabled
 pub struct DisabledIf<T, W> {
     inner: WidgetPod<T, W>,
     disabled_if: Box<dyn Fn(&T, &Env) -> bool>,
 }
 
 impl<T: Data, W: Widget<T>> DisabledIf<T, W> {
     /// Creates a new `DisabledIf` widget with the inner widget and the closure to decide if the
-    /// widget should be disabled.
+    /// widget should be [`disabled`].
+    ///
+    /// [`disabled`]: crate::EventCtx::is_disabled
     pub fn new(widget: W, disabled_if: impl Fn(&T, &Env) -> bool + 'static) -> Self {
         DisabledIf {
             inner: WidgetPod::new(widget),

druid/src/widget/widget_ext.rs

@@ -275,13 +275,13 @@ pub trait WidgetExt<T: Data>: Widget<T> + Sized + 'static {
     }
 
     /// Wrap this widget in a [`DisabledIf`] widget.
-    /// The provided closure will determine if the widget is disabled.
     ///
-    /// See [`is_disabled`] or [`set_disabled`] for more info about the disabled state.
+    /// The provided closure will determine if the widget is disabled.
+    /// See [`is_disabled`] or [`set_disabled`] for more info about disabled state.
     ///
-    /// [`is_disabled`]: struct.EventCtx.html#method.is_disabled
-    /// [`set_disabled`]: struct.EventCtx.html#method.set_disabled
-    /// [`DisabledIf`]: widget/struct.DisabledIf.html
+    /// [`is_disabled`]: crate::EventCtx::is_disabled
+    /// [`set_disabled`]: crate::EventCtx::set_disabled
+    /// [`DisabledIf`]: crate::widget::DisabledIf
     fn disabled_if(self, disabled_if: impl Fn(&T, &Env) -> bool + 'static) -> DisabledIf<T, Self> {
         DisabledIf::new(self, disabled_if)
     }