Merge pull request #89 from frewsxcv/constraints

Implement min/max window dimension constraints for MacOS.

examples/min_max_size.rs

@@ -0,0 +1,23 @@
+#[cfg(target_os = "android")]
+#[macro_use]
+extern crate android_glue;
+
+extern crate winit;
+
+#[cfg(target_os = "android")]
+android_start!(main);
+
+fn main() {
+    let window = winit::WindowBuilder::new()
+        .with_min_dimensions(400, 200)
+        .with_max_dimensions(800, 400)
+        .build()
+        .unwrap();
+
+    for event in window.wait_events() {
+        match event {
+            winit::Event::Closed => break,
+            _ => ()
+        }
+    }
+}

src/platform/macos/mod.rs

@@ -269,10 +269,6 @@ impl Window {
                pl_attribs: &PlatformSpecificWindowBuilderAttributes)
                -> Result<Window, CreationError>
     {
-        // not implemented
-        assert!(win_attribs.min_dimensions.is_none());
-        assert!(win_attribs.max_dimensions.is_none());
-
         // let app = match Window::create_app() {
         let app = match Window::create_app(pl_attribs.activation_policy) {
             Some(app) => app,
@@ -300,6 +296,14 @@ impl Window {
             } else {
                 window.makeKeyWindow();
             }
+
+            if let Some((width, height)) = win_attribs.min_dimensions {
+                nswindow_set_min_dimensions(window.0, width.into(), height.into());
+            }
+
+            if let Some((width, height)) = win_attribs.max_dimensions {
+                nswindow_set_max_dimensions(window.0, width.into(), height.into());
+            }
         }
 
         let ds = DelegateState {
@@ -627,6 +631,55 @@ impl Window {
     }
 }
 
+unsafe fn nswindow_set_min_dimensions<V: NSWindow + Copy>(
+    window: V, min_width: f64, min_height: f64)
+{
+    window.setMinSize_(NSSize {
+        width: min_width,
+        height: min_height,
+    });
+    // If necessary, resize the window to match constraint
+    let mut current_rect = NSWindow::frame(window);
+    if current_rect.size.width < min_width {
+        current_rect.size.width = min_width;
+        window.setFrame_display_(current_rect, 0)
+    }
+    if current_rect.size.height < min_height {
+        // The origin point of a rectangle is at its bottom left in Cocoa. To
+        // ensure the window's top-left point remains the same:
+        current_rect.origin.y +=
+            current_rect.size.height - min_height;
+
+        current_rect.size.height = min_height;
+        window.setFrame_display_(current_rect, 0)
+    }
+}
+
+unsafe fn nswindow_set_max_dimensions<V: NSWindow + Copy>(
+    window: V, max_width: f64, max_height: f64)
+{
+    window.setMaxSize_(NSSize {
+        width: max_width,
+        height: max_height,
+    });
+    // If necessary, resize the window to match constraint
+    let mut current_rect = NSWindow::frame(window);
+    if current_rect.size.width > max_width {
+        current_rect.size.width = max_width;
+        window.setFrame_display_(current_rect, 0)
+    }
+    if current_rect.size.height > max_height {
+        // The origin point of a rectangle is at its bottom left in
+        // Cocoa. To ensure the window's top-left point remains the
+        // same:
+        current_rect.origin.y +=
+            current_rect.size.height - max_height;
+
+        current_rect.size.height = max_height;
+        window.setFrame_display_(current_rect, 0)
+    }
+}
+
 struct IdRef(id);
 
 impl IdRef {