X11: Implement resize increments and base size (#494)

CHANGELOG.md

@@ -14,6 +14,7 @@
 - Various safety and correctness improvements to the X11 backend internals.
 - Fixed memory leak on X11 every time the mouse entered the window.
 - On X11, drag and drop now works reliably in release mode.
+- Added `WindowBuilderExt::with_resize_increments` and `WindowBuilderExt::with_base_size` to X11, allowing for more optional hints to be set.
 
 # Version 0.13.1 (2018-04-26)
 

src/os/unix.rs

@@ -199,6 +199,11 @@ impl WindowExt for Window {
 pub trait WindowBuilderExt {
     fn with_x11_visual<T>(self, visual_infos: *const T) -> WindowBuilder;
     fn with_x11_screen(self, screen_id: i32) -> WindowBuilder;
+
+    /// Build window with resize increment hint. Only implemented on X11.
+    fn with_resize_increments(self, width_inc: i32, height_inc: i32) -> WindowBuilder;
+    /// Build window with base size hint. Only implemented on X11.
+    fn with_base_size(self, base_width: i32, base_height: i32) -> WindowBuilder;
 }
 
 impl WindowBuilderExt for WindowBuilder {
@@ -215,6 +220,18 @@ impl WindowBuilderExt for WindowBuilder {
         self.platform_specific.screen_id = Some(screen_id);
         self
     }
+
+    #[inline]
+    fn with_resize_increments(mut self, width_inc: i32, height_inc: i32) -> WindowBuilder {
+        self.platform_specific.resize_increments = Some((width_inc, height_inc));
+        self
+    }
+
+    #[inline]
+    fn with_base_size(mut self, base_width: i32, base_height: i32) -> WindowBuilder {
+        self.platform_specific.base_size = Some((base_width, base_height));
+        self
+    }
 }
 
 /// Additional methods on `MonitorId` that are specific to Linux.

src/platform/linux/mod.rs

@@ -32,6 +32,8 @@ const BACKEND_PREFERENCE_ENV_VAR: &str = "WINIT_UNIX_BACKEND";
 pub struct PlatformSpecificWindowBuilderAttributes {
     pub visual_infos: Option<XVisualInfo>,
     pub screen_id: Option<i32>,
+    pub resize_increments: Option<(i32, i32)>,
+    pub base_size: Option<(i32, i32)>,
 }
 
 lazy_static!(

src/platform/linux/x11/window.rs

@@ -212,15 +212,25 @@ impl Window2 {
                 (*size_hints).flags = ffi::PSize;
                 (*size_hints).width = dimensions.0 as c_int;
                 (*size_hints).height = dimensions.1 as c_int;
-                if let Some(dimensions) = window_attrs.min_dimensions {
+                if let Some((min_width, min_height)) = window_attrs.min_dimensions {
                     (*size_hints).flags |= ffi::PMinSize;
-                    (*size_hints).min_width = dimensions.0 as c_int;
-                    (*size_hints).min_height = dimensions.1 as c_int;
+                    (*size_hints).min_width = min_width as c_int;
+                    (*size_hints).min_height = min_height as c_int;
                 }
-                if let Some(dimensions) = window_attrs.max_dimensions {
+                if let Some((max_width, max_height)) = window_attrs.max_dimensions {
                     (*size_hints).flags |= ffi::PMaxSize;
-                    (*size_hints).max_width = dimensions.0 as c_int;
-                    (*size_hints).max_height = dimensions.1 as c_int;
+                    (*size_hints).max_width = max_width as c_int;
+                    (*size_hints).max_height = max_height as c_int;
+                }
+                if let Some((width_inc, height_inc)) = pl_attribs.resize_increments {
+                    (*size_hints).flags |= ffi::PResizeInc;
+                    (*size_hints).width_inc = width_inc as c_int;
+                    (*size_hints).height_inc = height_inc as c_int;
+                }
+                if let Some((base_width, base_height)) = pl_attribs.base_size {
+                    (*size_hints).flags |= ffi::PBaseSize;
+                    (*size_hints).base_width = base_width as c_int;
+                    (*size_hints).base_height = base_height as c_int;
                 }
                 unsafe {
                     (xconn.xlib.XSetWMNormalHints)(