Add basic slider examples

imgui-examples/examples/slider.rs

@@ -0,0 +1,99 @@
+use imgui::*;
+
+mod support;
+
+fn main() {
+    let mut state = State::default();
+    let system = support::init(file!());
+    system.main_loop(move |run, ui| {
+        example_selector(run, ui, &mut state);
+        match state.example {
+            1 => example_1(ui, &mut state),
+            2 => example_2(ui, &mut state),
+            _ => (),
+        }
+    });
+}
+
+fn example_selector(run: &mut bool, ui: &mut Ui, state: &mut State) {
+    let w = Window::new(im_str!("Slider examples"))
+        .opened(run)
+        .position([20.0, 20.0], Condition::Appearing)
+        .size([700.0, 80.0], Condition::Appearing)
+        .resizable(false);
+    w.build(&ui, || {
+        let mut clicked = false;
+        clicked |= ui.radio_button(im_str!("Example 1: Basic sliders"), &mut state.example, 1);
+        clicked |= ui.radio_button(im_str!("Example 2: Slider arrays"), &mut state.example, 2);
+        if clicked {
+            state.reset();
+        }
+    });
+}
+
+fn example_1(ui: &Ui, state: &mut State) {
+    let w = Window::new(im_str!("Example 1: Basic sliders"))
+        .size([700.0, 340.0], Condition::Appearing)
+        .position([20.0, 120.0], Condition::Appearing);
+    w.build(&ui, || {
+        ui.text("All of the following data types are supported:");
+        ui.text("Signed:   i8 i16 i32 i64");
+        ui.text("Unsigned: u8 u16 u32 u64");
+        ui.text("Floats:   f32 f64");
+
+        Slider::new(im_str!("u8 value"))
+            .build(&ui, &mut state.u8_value);
+
+        Slider::new(im_str!("f32 value"))
+            .build(&ui, &mut state.f32_value);
+
+        ui.separator();
+        ui.text("Slider range can be limited:");
+        Slider::new(im_str!("i32 value with range"))
+            .range(-999 ..= 999)
+            .build(&ui, &mut state.i32_value);
+        ui.text("Note that for 32-bit/64-bit types, sliders are always limited to half of the natural type range!");
+
+        ui.separator();
+        ui.text("Value formatting can be customized with a C-style printf string:");
+        Slider::new(im_str!("f64 value with custom formatting"))
+            .range(-999_999_999.0 ..= 999_999_999.0)
+            .display_format(im_str!("%09.0f"))
+            .build(&ui, &mut state.f64_formatted);
+
+        ui.separator();
+        ui.text("Vertical sliders require a size parameter but otherwise work in a similar way:");
+        VerticalSlider::new(im_str!("vertical\nu8 value"), [50.0, 50.0])
+            .build(&ui, &mut state.u8_value);
+    });
+}
+
+fn example_2(ui: &Ui, state: &mut State) {
+    let w = Window::new(im_str!("Example 2: Slider arrays"))
+        .size([700.0, 260.0], Condition::Appearing)
+        .position([20.0, 120.0], Condition::Appearing);
+    w.build(&ui, || {
+        ui.text("You can easily build a slider group from an array of values:");
+        Slider::new(im_str!("[u8; 4]"))
+            .build_array(&ui, &mut state.array);
+
+        ui.text("You don't need to use arrays with known length; arbitrary slices can be used:");
+        let slice: &mut [u8] = &mut state.array[1..=2];
+        Slider::new(im_str!("subslice"))
+            .build_array(&ui, slice);
+    });
+}
+
+#[derive(Default)]
+struct State {
+    example: u32,
+    i32_value: i32,
+    u8_value: u8,
+    f32_value: f32,
+    f64_formatted: f64,
+    array: [u8; 4],
+}
+
+impl State {
+    fn reset(&mut self) {}
+}