From f98f11fabb13766274e18db667f1c74d75484479 Mon Sep 17 00:00:00 2001
From: Maurice Gilden <MauriceG@gmx.net>
Date: Sat, 18 Feb 2017 11:28:24 +0100
Subject: [PATCH] Added support for progress bar.

---
 CHANGELOG.markdown |  4 ++++
 src/lib.rs         | 17 ++++++++++++++
 src/progressbar.rs | 56 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 src/progressbar.rs

diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
index 584b27b..c8510db 100644
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+ - Support for progress bar
+
 ### Removed
 
 - `Window::always_vertical_scollbar` (typo)
diff --git a/src/lib.rs b/src/lib.rs
index 4392602..b8620cb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -45,6 +45,7 @@ pub use input::{ColorEdit3, ColorEdit4, InputFloat, InputFloat2, InputFloat3, In
 pub use menus::{Menu, MenuItem};
 pub use plothistogram::PlotHistogram;
 pub use plotlines::PlotLines;
+pub use progressbar::ProgressBar;
 pub use sliders::{SliderFloat, SliderInt};
 pub use trees::{CollapsingHeader, TreeNode};
 pub use window::Window;
@@ -53,6 +54,7 @@ mod input;
 mod menus;
 mod plothistogram;
 mod plotlines;
+mod progressbar;
 mod sliders;
 mod trees;
 mod window;
@@ -668,3 +670,18 @@ impl<'ui> Ui<'ui> {
         PlotHistogram::new(label, values)
     }
 }
+
+impl<'ui> Ui<'ui> {
+    /// Creates a progress bar. Fraction is the progress level with 0.0 = 0% and 1.0 = 100%.
+    ///
+    /// # Example
+    /// ```no_run
+    /// ui.progress_bar(0.6)
+    ///     .size(imgui::ImVec2::new(100.0, 12.0))
+    ///     .overlay_text(im_str!("Progress!"))
+    ///     .build();
+    /// ```
+    pub fn progress_bar<'p>(&self, fraction: f32) -> ProgressBar<'p> {
+        ProgressBar::new(fraction)
+    }
+}
diff --git a/src/progressbar.rs b/src/progressbar.rs
new file mode 100644
index 0000000..3820af0
--- /dev/null
+++ b/src/progressbar.rs
@@ -0,0 +1,56 @@
+#![warn(missing_docs)]
+
+use imgui_sys;
+use std::ptr;
+use super::{ImStr, ImVec2};
+
+
+/// Progress bar widget.
+#[must_use]
+pub struct ProgressBar<'p> {
+    fraction: f32,
+    size: ImVec2,
+    overlay_text: Option<ImStr<'p>>,
+}
+
+impl<'p> ProgressBar<'p> {
+    /// Creates a progress bar with a given fraction showing
+    /// the progress (0.0 = 0%, 1.0 = 100%).
+    /// The progress bar will be automatically sized to fill
+    /// the entire width of the window if no custom size is
+    /// specified.
+    pub fn new(fraction: f32) -> Self {
+        ProgressBar {
+            fraction: fraction,
+            size: ImVec2::new(-1.0, 0.0),
+            overlay_text: None,
+        }
+    }
+
+    /// Sets an optional text that will be drawn over the progress bar.
+    #[inline]
+    pub fn overlay_text(mut self, overlay_text: ImStr<'p>) -> Self {
+        self.overlay_text = Some(overlay_text);
+        self
+    }
+
+    /// Sets the size of the progress bar. Negative values will automatically
+    /// align to the end of the axis, zero will let the progress bar choose a 
+    /// size and positive values will use the given size.
+    #[inline]
+    pub fn size(mut self, size: ImVec2) -> Self {
+        self.size = size;
+        self
+    }
+
+    /// Builds the progress bar. This has to be called after setting all parameters
+    /// of the progress bar, otherwise the it will not be shown.
+    pub fn build(self) {
+        unsafe {
+            imgui_sys::igProgressBar(self.fraction,
+                                     &self.size,
+                                     self.overlay_text.map(|x| x.as_ptr()).unwrap_or(ptr::null())
+                                    );
+        }
+    }
+}
\ No newline at end of file