From 86ee32273f09719278000f4151fac63ca9e00057 Mon Sep 17 00:00:00 2001
From: Joonas Javanainen <joonas.javanainen@gmail.com>
Date: Fri, 12 Jul 2019 20:44:05 +0300
Subject: [PATCH] Add window scrolling API

---
 CHANGELOG.markdown   |  4 +++
 src/window/mod.rs    |  1 +
 src/window/scroll.rs | 66 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 src/window/scroll.rs

diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
index 3043353..04dd3aa 100644
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+- Window scrolling API
+
 ### Changed
 
 - Redesigned window API
diff --git a/src/window/mod.rs b/src/window/mod.rs
index 949aef6..11b93ed 100644
--- a/src/window/mod.rs
+++ b/src/window/mod.rs
@@ -8,6 +8,7 @@ use crate::sys;
 use crate::{Condition, Ui};
 
 pub(crate) mod content_region;
+pub(crate) mod scroll;
 
 bitflags! {
     /// Window hover check option flags
diff --git a/src/window/scroll.rs b/src/window/scroll.rs
new file mode 100644
index 0000000..8b48157
--- /dev/null
+++ b/src/window/scroll.rs
@@ -0,0 +1,66 @@
+use crate::sys;
+use crate::Ui;
+
+/// # Window scrolling
+impl<'ui> Ui<'ui> {
+    /// Returns the horizontal scrolling position.
+    ///
+    /// Value is between 0.0 and self.scroll_max_x().
+    pub fn scroll_x(&self) -> f32 {
+        unsafe { sys::igGetScrollX() }
+    }
+    /// Returns the vertical scrolling position.
+    ///
+    /// Value is between 0.0 and self.scroll_max_y().
+    pub fn scroll_y(&self) -> f32 {
+        unsafe { sys::igGetScrollY() }
+    }
+    /// Returns the maximum horizontal scrolling position.
+    ///
+    /// Roughly equal to content size X - window size X.
+    pub fn scroll_max_x(&self) -> f32 {
+        unsafe { sys::igGetScrollMaxX() }
+    }
+    /// Returns the maximum vertical scrolling position.
+    ///
+    /// Roughly equal to content size Y - window size Y.
+    pub fn scroll_max_y(&self) -> f32 {
+        unsafe { sys::igGetScrollMaxY() }
+    }
+    /// Set the horizontal scrolling position
+    pub fn set_scroll_x(&self, scroll_x: f32) {
+        unsafe { sys::igSetScrollX(scroll_x) };
+    }
+    /// Set the vertical scroll position
+    pub fn set_scroll_y(&self, scroll_y: f32) {
+        unsafe { sys::igSetScrollY(scroll_y) };
+    }
+    /// Adjust vertical scroll position to make the current cursor position visible
+    pub fn set_scroll_here_y(&self) {
+        unsafe { sys::igSetScrollHereY(0.5) };
+    }
+    /// Adjust vertical scroll position to make the current cursor position visible.
+    ///
+    /// center_y_ratio:
+    ///
+    /// - `0.0`: top
+    /// - `0.5`: center
+    /// - `1.0`: bottom
+    pub fn set_scroll_here_y_with_ratio(&self, center_y_ratio: f32) {
+        unsafe { sys::igSetScrollHereY(center_y_ratio) };
+    }
+    /// Adjust vertical scroll position to make the given position visible
+    pub fn set_scroll_from_pos_y(&self, local_y: f32) {
+        unsafe { sys::igSetScrollFromPosY(local_y, 0.5) };
+    }
+    /// Adjust vertical scroll position to make the given position visible.
+    ///
+    /// center_y_ratio:
+    ///
+    /// - `0.0`: top
+    /// - `0.5`: center
+    /// - `1.0`: bottom
+    pub fn set_scroll_from_pos_y_with_ratio(&self, local_y: f32, center_y_ratio: f32) {
+        unsafe { sys::igSetScrollFromPosY(local_y, center_y_ratio) };
+    }
+}