From aee594d23c709fa9c6b83e31aadef862f6eb5d9e Mon Sep 17 00:00:00 2001
From: Billy Messenger <BillyDM@protonmail.com>
Date: Thu, 15 Oct 2020 16:31:38 -0500
Subject: [PATCH] add window resize hints

---
 examples/open_window.rs   |  4 ++--
 src/lib.rs                | 17 +++++++++++++----
 src/x11/window.rs         | 38 +++++++++++++++++++++++++++++++++++---
 src/x11/xcb_connection.rs |  4 +++-
 4 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/examples/open_window.rs b/examples/open_window.rs
index 260e0ad..a764453 100644
--- a/examples/open_window.rs
+++ b/examples/open_window.rs
@@ -25,8 +25,8 @@ impl WindowHandler for MyProgram {
 fn main() {
     let window_open_options = baseview::WindowOpenOptions {
         title: "baseview".into(),
-        logical_width: 512,
-        logical_height: 512,
+        logical_size: (512, 512),
+        resize: baseview::WindowResize::None,
         scale: 1.0,
         parent: baseview::Parent::None,
     };
diff --git a/src/lib.rs b/src/lib.rs
index be05a54..c0531ff 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -32,13 +32,22 @@ pub enum Parent {
 
 unsafe impl Send for Parent {}
 
+pub enum WindowResize {
+    None,
+    MinMax {
+        min_logical_size: (u32, u32),
+        max_logical_size: (u32, u32),
+        keep_aspect: bool,
+    },
+}
+
 pub struct WindowOpenOptions {
     pub title: String,
 
-    /// The logical width of the window
-    pub logical_width: u32,
-    /// The logical height of the window
-    pub logical_height: u32,
+    /// The logical width and height of the window
+    pub logical_size: (u32, u32),
+
+    pub resize: WindowResize,
 
     /// The dpi scale factor. This will used in conjunction with the dpi scale
     /// factor of the system.
diff --git a/src/x11/window.rs b/src/x11/window.rs
index b4a56b4..a48bb46 100644
--- a/src/x11/window.rs
+++ b/src/x11/window.rs
@@ -12,7 +12,7 @@ use raw_window_handle::{
 use super::XcbConnection;
 use crate::{
     Event, KeyboardEvent, MouseButton, MouseCursor, MouseEvent, Parent, ScrollDelta, WindowEvent,
-    WindowHandle, WindowHandler, WindowInfo, WindowOpenOptions, WindowOpenResult,
+    WindowHandle, WindowHandler, WindowInfo, WindowOpenOptions, WindowOpenResult, WindowResize,
 };
 
 pub struct Window {
@@ -81,9 +81,10 @@ impl Window {
 
         let scaling = xcb_connection.get_scaling().unwrap_or(1.0) * options.scale;
 
+        let (logical_width, logical_height) = options.logical_size;
         let window_info = WindowInfo::from_logical_size(
-            options.logical_width,
-            options.logical_height,
+            logical_width,
+            logical_height,
             scaling
         );
 
@@ -126,6 +127,37 @@ impl Window {
             title.as_bytes(),
         );
 
+        match options.resize {
+            WindowResize::MinMax { min_logical_size, max_logical_size, keep_aspect } => {
+                let size_hints = if keep_aspect {
+                    xcb_util::icccm::SizeHints::empty()
+                        .min_size(min_logical_size.0 as i32, min_logical_size.1 as i32)
+                        .max_size(max_logical_size.0 as i32, max_logical_size.1 as i32)
+                        .aspect(
+                            (min_logical_size.0 as i32, min_logical_size.1 as i32),
+                            (max_logical_size.0 as i32, max_logical_size.1 as i32),
+                        )
+                        .build()
+                } else {
+                    xcb_util::icccm::SizeHints::empty()
+                        .min_size(min_logical_size.0 as i32, min_logical_size.1 as i32)
+                        .max_size(max_logical_size.0 as i32, max_logical_size.1 as i32)
+                        .build()
+                };
+
+                xcb_connection.atoms.wm_normal_hints
+                    .map(|wm_normal_hints| {
+                        xcb_util::icccm::set_wm_size_hints(
+                            &xcb_connection.conn,
+                            window_id,
+                            wm_normal_hints,
+                            &size_hints,
+                        );
+                    });
+            }
+            _ => {}
+        }
+
         xcb_connection.atoms.wm_protocols
             .zip(xcb_connection.atoms.wm_delete_window)
             .map(|(wm_protocols, wm_delete_window)| {
diff --git a/src/x11/xcb_connection.rs b/src/x11/xcb_connection.rs
index 3819ee6..db2113a 100644
--- a/src/x11/xcb_connection.rs
+++ b/src/x11/xcb_connection.rs
@@ -13,6 +13,7 @@ use super::cursor;
 pub(crate) struct Atoms {
     pub wm_protocols: Option<u32>,
     pub wm_delete_window: Option<u32>,
+    pub wm_normal_hints: Option<u32>,
 }
 
 pub struct XcbConnection {
@@ -45,7 +46,7 @@ impl XcbConnection {
     pub fn new() -> Result<Self, xcb::base::ConnError> {
         let (conn, xlib_display) = xcb::Connection::connect_with_xlib_display()?;
 
-        let (wm_protocols, wm_delete_window) = intern_atoms!(&conn, WM_PROTOCOLS, WM_DELETE_WINDOW);
+        let (wm_protocols, wm_delete_window, wm_normal_hints) = intern_atoms!(&conn, WM_PROTOCOLS, WM_DELETE_WINDOW, WM_NORMAL_HINTS);
 
         Ok(Self {
             conn,
@@ -54,6 +55,7 @@ impl XcbConnection {
             atoms: Atoms {
                 wm_protocols,
                 wm_delete_window,
+                wm_normal_hints,
             },
 
             cursor_cache: HashMap::new()