Merge pull request #354 from hecrj/feature/glow-renderer

OpenGL renderer and backend-agnostic graphics subcrate

1 files changed, 118 insertions, 0 deletions

diff --git a/graphics/src/widget/pane_grid.rs b/graphics/src/widget/pane_grid.rs
new file mode 100644
index 00000000..56af683d
--- /dev/null
+++ b/graphics/src/widget/pane_grid.rs
@@ -0,0 +1,118 @@
+//! Let your users split regions of your application and organize layout dynamically.
+//!
+//! [![Pane grid - Iced](https://thumbs.gfycat.com/MixedFlatJellyfish-small.gif)](https://gfycat.com/mixedflatjellyfish)
+//!
+//! # Example
+//! The [`pane_grid` example] showcases how to use a [`PaneGrid`] with resizing,
+//! drag and drop, and hotkey support.
+//!
+//! [`pane_grid` example]: https://github.com/hecrj/iced/tree/0.1/examples/pane_grid
+//! [`PaneGrid`]: type.PaneGrid.html
+use crate::{Backend, Primitive, Renderer};
+use iced_native::mouse;
+use iced_native::pane_grid;
+use iced_native::{Element, Layout, Point, Rectangle, Vector};
+
+pub use iced_native::pane_grid::{
+    Axis, Direction, DragEvent, Focus, KeyPressEvent, Pane, ResizeEvent, Split,
+    State,
+};
+
+/// A collection of panes distributed using either vertical or horizontal splits
+/// to completely fill the space available.
+///
+/// [![Pane grid - Iced](https://thumbs.gfycat.com/MixedFlatJellyfish-small.gif)](https://gfycat.com/mixedflatjellyfish)
+///
+/// This is an alias of an `iced_native` pane grid with an `iced_wgpu::Renderer`.
+pub type PaneGrid<'a, Message, Backend> =
+    iced_native::PaneGrid<'a, Message, Renderer<Backend>>;
+
+impl<B> pane_grid::Renderer for Renderer<B>
+where
+    B: Backend,
+{
+    fn draw<Message>(
+        &mut self,
+        defaults: &Self::Defaults,
+        content: &[(Pane, Element<'_, Message, Self>)],
+        dragging: Option<Pane>,
+        resizing: Option<Axis>,
+        layout: Layout<'_>,
+        cursor_position: Point,
+    ) -> Self::Output {
+        let pane_cursor_position = if dragging.is_some() {
+            // TODO: Remove once cursor availability is encoded in the type
+            // system
+            Point::new(-1.0, -1.0)
+        } else {
+            cursor_position
+        };
+
+        let mut mouse_interaction = mouse::Interaction::default();
+        let mut dragged_pane = None;
+
+        let mut panes: Vec<_> = content
+            .iter()
+            .zip(layout.children())
+            .enumerate()
+            .map(|(i, ((id, pane), layout))| {
+                let (primitive, new_mouse_interaction) =
+                    pane.draw(self, defaults, layout, pane_cursor_position);
+
+                if new_mouse_interaction > mouse_interaction {
+                    mouse_interaction = new_mouse_interaction;
+                }
+
+                if Some(*id) == dragging {
+                    dragged_pane = Some((i, layout));
+                }
+
+                primitive
+            })
+            .collect();
+
+        let primitives = if let Some((index, layout)) = dragged_pane {
+            let pane = panes.remove(index);
+            let bounds = layout.bounds();
+
+            // TODO: Fix once proper layering is implemented.
+            // This is a pretty hacky way to achieve layering.
+            let clip = Primitive::Clip {
+                bounds: Rectangle {
+                    x: cursor_position.x - bounds.width / 2.0,
+                    y: cursor_position.y - bounds.height / 2.0,
+                    width: bounds.width + 0.5,
+                    height: bounds.height + 0.5,
+                },
+                offset: Vector::new(0, 0),
+                content: Box::new(Primitive::Translate {
+                    translation: Vector::new(
+                        cursor_position.x - bounds.x - bounds.width / 2.0,
+                        cursor_position.y - bounds.y - bounds.height / 2.0,
+                    ),
+                    content: Box::new(pane),
+                }),
+            };
+
+            panes.push(clip);
+
+            panes
+        } else {
+            panes
+        };
+
+        (
+            Primitive::Group { primitives },
+            if dragging.is_some() {
+                mouse::Interaction::Grabbing
+            } else if let Some(axis) = resizing {
+                match axis {
+                    Axis::Horizontal => mouse::Interaction::ResizingVertically,
+                    Axis::Vertical => mouse::Interaction::ResizingHorizontally,
+                }
+            } else {
+                mouse_interaction
+            },
+        )
+    }
+}