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ErrorBoundaryBuilder

telex

Struct ErrorBoundaryBuilder 

Source 
pub struct ErrorBoundaryBuilder { /* private fields */ }
Expand description

Builder for error boundary views.

Implementations§

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impl ErrorBoundaryBuilder

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pub fn new() -> Self

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pub fn child(self, child: View) -> Self

Set the child view (the view that might panic).

Examples found in repository?
examples/37_error_boundary.rs (line 71)
38    fn render(&self, cx: Scope) -> View {
39        let show_help = state!(cx, || false);
40
41        cx.use_command(
42            KeyBinding::key(KeyCode::F(1)),
43            with!(show_help => move || show_help.update(|v| *v = !*v)),
44        );
45
46        let count = state!(cx, || 0i32);
47
48        // The panic must happen at render time (inside render_view) so the
49        // error boundary's catch_unwind can catch it. A custom widget defers
50        // execution to the render pass.
51        let risky_view = View::custom(std::rc::Rc::new(std::cell::RefCell::new(RiskyCounter(count.get()))));
52
53        let fallback = View::vstack()
54            .child(View::styled_text("CAUGHT PANIC").color(Color::Red).bold().build())
55            .child(View::text("The child view panicked."))
56            .child(View::text("But the app is still running!"))
57            .build();
58
59        View::vstack()
60            .spacing(1)
61            .child(View::styled_text("Error Boundary Demo").bold().build())
62            .child(
63                View::hstack()
64                    .spacing(2)
65                    .child(
66                        View::vstack()
67                            .spacing(1)
68                            .child(View::styled_text("Protected Panel").bold().build())
69                            .child(
70                                View::error_boundary()
71                                    .child(risky_view)
72                                    .fallback(fallback)
73                                    .build(),
74                            )
75                            .build(),
76                    )
77                    .child(
78                        View::vstack()
79                            .spacing(1)
80                            .child(View::styled_text("How It Works").bold().build())
81                            .child(View::text("The left panel asserts"))
82                            .child(View::text("count < 5. When it hits"))
83                            .child(View::text("5, the error boundary"))
84                            .child(View::text("catches the panic and"))
85                            .child(View::text("renders the fallback."))
86                            .build(),
87                    )
88                    .build(),
89            )
90            .child(
91                View::hstack()
92                    .spacing(1)
93                    .child(
94                        View::button()
95                            .label("[ + Increment ]")
96                            .on_press(with!(count => move || count.update(|n| *n += 1)))
97                            .build(),
98                    )
99                    .child(
100                        View::button()
101                            .label("[ Reset to 0 ]")
102                            .on_press(with!(count => move || count.set(0)))
103                            .build(),
104                    )
105                    .child(View::styled_text(format!("count = {}", count.get())).dim().build())
106                    .build(),
107            )
108            .child(View::styled_text("F1 help • Ctrl+Q quit").dim().build())
109            .child(
110                View::modal()
111                    .visible(show_help.get())
112                    .title("Example 37: Error Boundary")
113                    .on_dismiss(with!(show_help => move || show_help.set(false)))
114                    .child(
115                        View::vstack()
116                            .child(View::styled_text("What you're seeing").bold().build())
117                            .child(View::text("• A counter that panics at 5"))
118                            .child(View::text("• Error boundary catches the panic"))
119                            .child(View::text("• Red fallback replaces the crash"))
120                            .child(View::gap(1))
121                            .child(View::styled_text("Key concepts").bold().build())
122                            .child(View::text("• View::error_boundary()"))
123                            .child(View::text("• .child(risky) .fallback(safe)"))
124                            .child(View::text("• Panics are caught, not propagated"))
125                            .child(View::text("• App keeps running after panic"))
126                            .child(View::gap(1))
127                            .child(View::styled_text("Try this").bold().build())
128                            .child(View::text("• Increment to 5 to trigger panic"))
129                            .child(View::text("• Reset to 0 to recover"))
130                            .child(View::text("• Keep incrementing past 5"))
131                            .child(View::gap(1))
132                            .child(View::styled_text("Next up").bold().build())
133                            .child(View::text("-> 38_custom_widget: Game of Life"))
134                            .child(View::gap(1))
135                            .child(View::styled_text("Press Escape to close").dim().build())
136                            .build(),
137                    )
138                    .build(),
139            )
140            .build()
141    }
Source

pub fn fallback(self, fallback: View) -> Self

Set the fallback view (shown when child panics).

Examples found in repository?
examples/37_error_boundary.rs (line 72)
38    fn render(&self, cx: Scope) -> View {
39        let show_help = state!(cx, || false);
40
41        cx.use_command(
42            KeyBinding::key(KeyCode::F(1)),
43            with!(show_help => move || show_help.update(|v| *v = !*v)),
44        );
45
46        let count = state!(cx, || 0i32);
47
48        // The panic must happen at render time (inside render_view) so the
49        // error boundary's catch_unwind can catch it. A custom widget defers
50        // execution to the render pass.
51        let risky_view = View::custom(std::rc::Rc::new(std::cell::RefCell::new(RiskyCounter(count.get()))));
52
53        let fallback = View::vstack()
54            .child(View::styled_text("CAUGHT PANIC").color(Color::Red).bold().build())
55            .child(View::text("The child view panicked."))
56            .child(View::text("But the app is still running!"))
57            .build();
58
59        View::vstack()
60            .spacing(1)
61            .child(View::styled_text("Error Boundary Demo").bold().build())
62            .child(
63                View::hstack()
64                    .spacing(2)
65                    .child(
66                        View::vstack()
67                            .spacing(1)
68                            .child(View::styled_text("Protected Panel").bold().build())
69                            .child(
70                                View::error_boundary()
71                                    .child(risky_view)
72                                    .fallback(fallback)
73                                    .build(),
74                            )
75                            .build(),
76                    )
77                    .child(
78                        View::vstack()
79                            .spacing(1)
80                            .child(View::styled_text("How It Works").bold().build())
81                            .child(View::text("The left panel asserts"))
82                            .child(View::text("count < 5. When it hits"))
83                            .child(View::text("5, the error boundary"))
84                            .child(View::text("catches the panic and"))
85                            .child(View::text("renders the fallback."))
86                            .build(),
87                    )
88                    .build(),
89            )
90            .child(
91                View::hstack()
92                    .spacing(1)
93                    .child(
94                        View::button()
95                            .label("[ + Increment ]")
96                            .on_press(with!(count => move || count.update(|n| *n += 1)))
97                            .build(),
98                    )
99                    .child(
100                        View::button()
101                            .label("[ Reset to 0 ]")
102                            .on_press(with!(count => move || count.set(0)))
103                            .build(),
104                    )
105                    .child(View::styled_text(format!("count = {}", count.get())).dim().build())
106                    .build(),
107            )
108            .child(View::styled_text("F1 help • Ctrl+Q quit").dim().build())
109            .child(
110                View::modal()
111                    .visible(show_help.get())
112                    .title("Example 37: Error Boundary")
113                    .on_dismiss(with!(show_help => move || show_help.set(false)))
114                    .child(
115                        View::vstack()
116                            .child(View::styled_text("What you're seeing").bold().build())
117                            .child(View::text("• A counter that panics at 5"))
118                            .child(View::text("• Error boundary catches the panic"))
119                            .child(View::text("• Red fallback replaces the crash"))
120                            .child(View::gap(1))
121                            .child(View::styled_text("Key concepts").bold().build())
122                            .child(View::text("• View::error_boundary()"))
123                            .child(View::text("• .child(risky) .fallback(safe)"))
124                            .child(View::text("• Panics are caught, not propagated"))
125                            .child(View::text("• App keeps running after panic"))
126                            .child(View::gap(1))
127                            .child(View::styled_text("Try this").bold().build())
128                            .child(View::text("• Increment to 5 to trigger panic"))
129                            .child(View::text("• Reset to 0 to recover"))
130                            .child(View::text("• Keep incrementing past 5"))
131                            .child(View::gap(1))
132                            .child(View::styled_text("Next up").bold().build())
133                            .child(View::text("-> 38_custom_widget: Game of Life"))
134                            .child(View::gap(1))
135                            .child(View::styled_text("Press Escape to close").dim().build())
136                            .build(),
137                    )
138                    .build(),
139            )
140            .build()
141    }
Source

pub fn build(self) -> View

Examples found in repository?
examples/37_error_boundary.rs (line 73)
38    fn render(&self, cx: Scope) -> View {
39        let show_help = state!(cx, || false);
40
41        cx.use_command(
42            KeyBinding::key(KeyCode::F(1)),
43            with!(show_help => move || show_help.update(|v| *v = !*v)),
44        );
45
46        let count = state!(cx, || 0i32);
47
48        // The panic must happen at render time (inside render_view) so the
49        // error boundary's catch_unwind can catch it. A custom widget defers
50        // execution to the render pass.
51        let risky_view = View::custom(std::rc::Rc::new(std::cell::RefCell::new(RiskyCounter(count.get()))));
52
53        let fallback = View::vstack()
54            .child(View::styled_text("CAUGHT PANIC").color(Color::Red).bold().build())
55            .child(View::text("The child view panicked."))
56            .child(View::text("But the app is still running!"))
57            .build();
58
59        View::vstack()
60            .spacing(1)
61            .child(View::styled_text("Error Boundary Demo").bold().build())
62            .child(
63                View::hstack()
64                    .spacing(2)
65                    .child(
66                        View::vstack()
67                            .spacing(1)
68                            .child(View::styled_text("Protected Panel").bold().build())
69                            .child(
70                                View::error_boundary()
71                                    .child(risky_view)
72                                    .fallback(fallback)
73                                    .build(),
74                            )
75                            .build(),
76                    )
77                    .child(
78                        View::vstack()
79                            .spacing(1)
80                            .child(View::styled_text("How It Works").bold().build())
81                            .child(View::text("The left panel asserts"))
82                            .child(View::text("count < 5. When it hits"))
83                            .child(View::text("5, the error boundary"))
84                            .child(View::text("catches the panic and"))
85                            .child(View::text("renders the fallback."))
86                            .build(),
87                    )
88                    .build(),
89            )
90            .child(
91                View::hstack()
92                    .spacing(1)
93                    .child(
94                        View::button()
95                            .label("[ + Increment ]")
96                            .on_press(with!(count => move || count.update(|n| *n += 1)))
97                            .build(),
98                    )
99                    .child(
100                        View::button()
101                            .label("[ Reset to 0 ]")
102                            .on_press(with!(count => move || count.set(0)))
103                            .build(),
104                    )
105                    .child(View::styled_text(format!("count = {}", count.get())).dim().build())
106                    .build(),
107            )
108            .child(View::styled_text("F1 help • Ctrl+Q quit").dim().build())
109            .child(
110                View::modal()
111                    .visible(show_help.get())
112                    .title("Example 37: Error Boundary")
113                    .on_dismiss(with!(show_help => move || show_help.set(false)))
114                    .child(
115                        View::vstack()
116                            .child(View::styled_text("What you're seeing").bold().build())
117                            .child(View::text("• A counter that panics at 5"))
118                            .child(View::text("• Error boundary catches the panic"))
119                            .child(View::text("• Red fallback replaces the crash"))
120                            .child(View::gap(1))
121                            .child(View::styled_text("Key concepts").bold().build())
122                            .child(View::text("• View::error_boundary()"))
123                            .child(View::text("• .child(risky) .fallback(safe)"))
124                            .child(View::text("• Panics are caught, not propagated"))
125                            .child(View::text("• App keeps running after panic"))
126                            .child(View::gap(1))
127                            .child(View::styled_text("Try this").bold().build())
128                            .child(View::text("• Increment to 5 to trigger panic"))
129                            .child(View::text("• Reset to 0 to recover"))
130                            .child(View::text("• Keep incrementing past 5"))
131                            .child(View::gap(1))
132                            .child(View::styled_text("Next up").bold().build())
133                            .child(View::text("-> 38_custom_widget: Game of Life"))
134                            .child(View::gap(1))
135                            .child(View::styled_text("Press Escape to close").dim().build())
136                            .build(),
137                    )
138                    .build(),
139            )
140            .build()
141    }

Trait Implementations§

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impl Default for ErrorBoundaryBuilder

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fn default() -> ErrorBoundaryBuilder

Returns the “default value” for a type. Read more

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where T: 'static + ?Sized,

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fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

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Convert &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s.
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Convert &mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &mut Any’s vtable from &mut Trait’s.
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Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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type Error = Infallible

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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.