Autoresizing window and friends

examples/test_window.rs

@@ -30,6 +30,7 @@ struct State {
     no_collapse: bool,
     no_menu: bool,
     bg_alpha: f32,
+    auto_resize_state: AutoResizeState,
     file_menu: FileMenuState
 }
 
@@ -55,6 +56,7 @@ impl Default for State {
             no_collapse: false,
             no_menu: false,
             bg_alpha: 0.65,
+            auto_resize_state: Default::default(),
             file_menu: Default::default()
         }
     }
@@ -72,6 +74,18 @@ impl Default for FileMenuState {
     }
 }
 
+struct AutoResizeState {
+    lines: usize
+}
+
+impl Default for AutoResizeState {
+    fn default() -> Self {
+        AutoResizeState {
+            lines: 10
+        }
+    }
+}
+
 fn main() {
     let mut state = State {
         .. Default::default()
@@ -110,6 +124,9 @@ fn show_test_window<'a>(frame: &Frame<'a>, state: &mut State) -> bool {
         state.show_app_metrics = frame.show_metrics_window();
     }
     if state.show_app_main_menu_bar { show_example_app_main_menu_bar(frame, state) }
+    if state.show_app_auto_resize {
+        state.show_app_auto_resize = show_example_app_auto_resize(frame, &mut state.auto_resize_state);
+    }
     if state.show_app_fixed_overlay {
         state.show_app_fixed_overlay = show_example_app_fixed_overlay(frame);
     }
@@ -243,6 +260,25 @@ fn show_example_menu_file<'a>(frame: &Frame<'a>, state: &mut FileMenuState) {
     if frame.menu_item(im_str!("Quit")).shortcut(im_str!("Alt+F4")).build() { }
 }
 
+fn show_example_app_auto_resize<'a>(frame: &Frame<'a>, state: &mut AutoResizeState) -> bool {
+    frame.window()
+        .name(im_str!("Example: Auto-resizing window"))
+        .closable(true)
+        .always_auto_resize(true)
+        .build(|| {
+            frame.text(im_str!("Window will resize every-frame to the size of its content.
+Note that you probably don't want to query the window size to
+output your content because that would create a feedback loop."));
+            if let Some(lines) = frame.slider_i32(im_str!("Number of lines"),
+                                                  state.lines as i32, 1, 20).build() {
+              state.lines = lines as usize;
+            }
+            for i in 0 .. state.lines {
+                frame.text(im_str!("{:2$}This is line {}", "", i, i * 4));
+            }
+        })
+}
+
 fn show_example_app_fixed_overlay<'a>(frame: &Frame<'a>) -> bool {
     frame.window()
         .name(im_str!("Example: Fixed Overlay"))

src/lib.rs

@@ -31,11 +31,13 @@ pub use ffi::{
    ImVec2, ImVec4
 };
 pub use menus::{Menu, MenuItem};
+pub use sliders::{SliderInt};
 pub use widgets::{CollapsingHeader};
 pub use window::{Window};
 
 pub mod ffi;
 mod menus;
+mod sliders;
 mod widgets;
 mod window;
 
@@ -276,6 +278,14 @@ impl<'fr> Frame<'fr> {
    }
 }
 
+// Widgets: Sliders
+impl<'fr> Frame<'fr> {
+   pub fn slider_i32<'p>(&self, label: ImStr<'p>,
+                         value: i32, min: i32, max: i32) -> SliderInt<'fr, 'p> {
+      SliderInt::new(label, value, min, max)
+   }
+}
+
 // Widgets: Menus
 impl<'fr> Frame<'fr> {
    pub fn main_menu_bar<F>(&self, f: F) where F: FnOnce() {

src/sliders.rs

@@ -0,0 +1,48 @@
+use libc::c_int;
+use std::marker::PhantomData;
+
+use super::ffi;
+use super::{Frame, ImStr};
+
+// TODO: Consider using Range, even though it is half-open
+
+pub struct SliderInt<'fr, 'p> {
+   label: ImStr<'p>,
+   value: i32,
+   min: i32,
+   max: i32,
+   display_format: ImStr<'p>,
+   _phantom: PhantomData<&'fr Frame<'fr>>
+}
+
+impl<'fr, 'p> SliderInt<'fr, 'p> {
+   pub fn new(label: ImStr<'p>, value: i32, min: i32, max: i32) -> Self {
+      SliderInt {
+         label: label,
+         value: value,
+         min: min,
+         max: max,
+         display_format: unsafe { ImStr::from_bytes(b"%.0f") },
+         _phantom: PhantomData
+      }
+   }
+   #[inline]
+   pub fn display_format(self, display_format: ImStr<'p>) -> Self {
+      SliderInt {
+         display_format: display_format,
+         .. self
+      }
+   }
+   pub fn build(self) -> Option<i32> {
+      let mut value = self.value as c_int;
+      let changed = unsafe {
+         ffi::igSliderInt(self.label.as_ptr(),
+            &mut value,
+            self.min as c_int,
+            self.max as c_int,
+            self.display_format.as_ptr()
+         )
+      };
+      if changed { Some(value as i32) } else { None }
+   }
+}