Also set the preferred size for the GridLayout

Issue #182

sixtyfps_runtime/corelib/layout.rs

@@ -293,7 +293,7 @@ pub fn solve_grid_layout(data: &GridLayoutData) {
         let row_max = cnstr.max_height.min(data.height * cnstr.max_height_percent / 100.);
         let row_min = cnstr.min_height.max(data.height * cnstr.min_height_percent / 100.)
             / (cell.rowspan as f32);
-        let row_pref = row_min;
+        let row_pref = cnstr.preferred_height;
 
         for r in 0..(cell.rowspan as usize) {
             let rdata = &mut row_layout_data[cell.row as usize + r];
@@ -306,7 +306,7 @@ pub fn solve_grid_layout(data: &GridLayoutData) {
         let col_max = cnstr.max_width.min(data.width * cnstr.max_width_percent / 100.);
         let col_min = cnstr.min_width.max(data.width * cnstr.min_width_percent / 100.)
             / (cell.colspan as f32);
-        let col_pref = col_min;
+        let col_pref = cnstr.preferred_width;
 
         for c in 0..(cell.colspan as usize) {
             let cdata = &mut col_layout_data[cell.col as usize + c];

tests/cases/layout/grid_preferred_size.60

@@ -0,0 +1,65 @@
+/* LICENSE BEGIN
+    This file is part of the SixtyFPS Project -- https://sixtyfps.io
+    Copyright (c) 2020 Olivier Goffart <olivier.goffart@sixtyfps.io>
+    Copyright (c) 2020 Simon Hausmann <simon.hausmann@sixtyfps.io>
+
+    SPDX-License-Identifier: GPL-3.0-only
+    This file is also available under commercial licensing terms.
+    Please contact info@sixtyfps.io for more information.
+LICENSE END */
+TestCase := Rectangle {
+    background: green;
+    width: 300phx;
+    height: 50phx;
+
+    GridLayout {
+        padding: 0px;
+        fake-image := Rectangle {
+            background: blue;
+            preferred-width: 25phx;
+            // Don't apply the preferred height for the horizontal layout.
+            preferred-height: 500phx;
+            horizontal-stretch: 0;
+            vertical-stretch: 0;
+        }
+        Rectangle {
+            background: green;
+            // implicit: horizontal-stretch: 1
+        }
+        Rectangle {
+            row: 1;
+            background: red;
+            // implicit: horizontal-stretch: 1
+        }
+    }
+
+    property <bool> fake-image-width-ok: fake-image.width == 25phx;
+    property <bool> fake-image-height-ok: fake-image.height == 50phx;
+}
+
+/*
+
+```cpp
+auto handle = TestCase::create();
+const TestCase &instance = *handle;
+TestCase::apply_layout({&TestCase::static_vtable, const_cast<TestCase*>(&instance) }, sixtyfps::Rect{0, 0, 300, 300});
+assert(instance.get_fake_image_width_ok());
+assert(instance.get_fake_image_height_ok());
+```
+
+
+```rust
+let instance = TestCase::new();
+sixtyfps::testing::apply_layout(&instance, sixtyfps::re_exports::Rect::new(Default::default(), sixtyfps::re_exports::Size::new(300., 300.)));
+assert!(instance.get_fake_image_width_ok());
+assert!(instance.get_fake_image_height_ok());
+```
+
+```js
+var instance = new sixtyfps.TestCase();
+instance.send_mouse_click(5., 5.);
+assert(instance.fake_image_width_ok);
+assert(instance.fake_image_height_ok);
+```
+
+*/