update theme

crates/ui/src/resizable/mod.rs

@@ -1,24 +1,294 @@
-use gpui::{Axis, Context, Window};
+use std::ops::Range;
+
+use gpui::{
+    px, Along, App, Axis, Bounds, Context, ElementId, EventEmitter, IsZero, Pixels, Window,
+};
+
 mod panel;
 mod resize_handle;
-
 pub use panel::*;
 pub(crate) use resize_handle::*;
 
-pub fn h_resizable(
-    window: &mut Window,
-    cx: &mut Context<ResizablePanelGroup>,
-) -> ResizablePanelGroup {
-    ResizablePanelGroup::new(window, cx).axis(Axis::Horizontal)
+pub(crate) const PANEL_MIN_SIZE: Pixels = px(100.);
+
+/// Create a [`ResizablePanelGroup`] with horizontal resizing
+pub fn h_resizable(id: impl Into<ElementId>) -> ResizablePanelGroup {
+    ResizablePanelGroup::new(id).axis(Axis::Horizontal)
 }
 
-pub fn v_resizable(
-    window: &mut Window,
-    cx: &mut Context<ResizablePanelGroup>,
-) -> ResizablePanelGroup {
-    ResizablePanelGroup::new(window, cx).axis(Axis::Vertical)
+/// Create a [`ResizablePanelGroup`] with vertical resizing
+pub fn v_resizable(id: impl Into<ElementId>) -> ResizablePanelGroup {
+    ResizablePanelGroup::new(id).axis(Axis::Vertical)
 }
 
+/// Create a [`ResizablePanel`].
 pub fn resizable_panel() -> ResizablePanel {
     ResizablePanel::new()
 }
+
+/// State for a [`ResizablePanel`]
+#[derive(Debug, Clone)]
+pub struct ResizableState {
+    /// The `axis` will sync to actual axis of the ResizablePanelGroup in use.
+    axis: Axis,
+    panels: Vec<ResizablePanelState>,
+    sizes: Vec<Pixels>,
+    pub(crate) resizing_panel_ix: Option<usize>,
+    bounds: Bounds<Pixels>,
+}
+
+impl Default for ResizableState {
+    fn default() -> Self {
+        Self {
+            axis: Axis::Horizontal,
+            panels: vec![],
+            sizes: vec![],
+            resizing_panel_ix: None,
+            bounds: Bounds::default(),
+        }
+    }
+}
+
+impl ResizableState {
+    /// Get the size of the panels.
+    pub fn sizes(&self) -> &Vec<Pixels> {
+        &self.sizes
+    }
+
+    pub(crate) fn insert_panel(
+        &mut self,
+        size: Option<Pixels>,
+        ix: Option<usize>,
+        cx: &mut Context<Self>,
+    ) {
+        let panel_state = ResizablePanelState {
+            size,
+            ..Default::default()
+        };
+
+        let size = size.unwrap_or(PANEL_MIN_SIZE);
+
+        // We make sure that the size always sums up to the container size
+        // by reducing the size of all other panels first.
+        let container_size = self.container_size().max(px(1.));
+        let total_leftover_size = (container_size - size).max(px(1.));
+
+        for (i, panel) in self.panels.iter_mut().enumerate() {
+            let ratio = self.sizes[i] / container_size;
+            self.sizes[i] = total_leftover_size * ratio;
+            panel.size = Some(self.sizes[i]);
+        }
+
+        if let Some(ix) = ix {
+            self.panels.insert(ix, panel_state);
+            self.sizes.insert(ix, size);
+        } else {
+            self.panels.push(panel_state);
+            self.sizes.push(size);
+        };
+
+        cx.notify();
+    }
+
+    pub(crate) fn sync_panels_count(
+        &mut self,
+        axis: Axis,
+        panels_count: usize,
+        cx: &mut Context<Self>,
+    ) {
+        let mut changed = self.axis != axis;
+        self.axis = axis;
+
+        if panels_count > self.panels.len() {
+            let diff = panels_count - self.panels.len();
+            self.panels
+                .extend(vec![ResizablePanelState::default(); diff]);
+            self.sizes.extend(vec![PANEL_MIN_SIZE; diff]);
+            changed = true;
+        }
+
+        if panels_count < self.panels.len() {
+            self.panels.truncate(panels_count);
+            self.sizes.truncate(panels_count);
+            changed = true;
+        }
+
+        if changed {
+            // We need to make sure the total size is in line with the container size.
+            self.adjust_to_container_size(cx);
+        }
+    }
+
+    pub(crate) fn update_panel_size(
+        &mut self,
+        panel_ix: usize,
+        bounds: Bounds<Pixels>,
+        size_range: Range<Pixels>,
+        cx: &mut Context<Self>,
+    ) {
+        let size = bounds.size.along(self.axis);
+        // This check is only necessary to stop the very first panel from resizing on its own
+        // it needs to be passed when the panel is freshly created so we get the initial size,
+        // but its also fine when it sometimes passes later.
+        if self.sizes[panel_ix].to_f64() == PANEL_MIN_SIZE.to_f64() {
+            self.sizes[panel_ix] = size;
+            self.panels[panel_ix].size = Some(size);
+        }
+        self.panels[panel_ix].bounds = bounds;
+        self.panels[panel_ix].size_range = size_range;
+        cx.notify();
+    }
+
+    pub(crate) fn remove_panel(&mut self, panel_ix: usize, cx: &mut Context<Self>) {
+        self.panels.remove(panel_ix);
+        self.sizes.remove(panel_ix);
+        if let Some(resizing_panel_ix) = self.resizing_panel_ix {
+            if resizing_panel_ix > panel_ix {
+                self.resizing_panel_ix = Some(resizing_panel_ix - 1);
+            }
+        }
+        self.adjust_to_container_size(cx);
+    }
+
+    pub(crate) fn replace_panel(
+        &mut self,
+        panel_ix: usize,
+        panel: ResizablePanelState,
+        cx: &mut Context<Self>,
+    ) {
+        let old_size = self.sizes[panel_ix];
+
+        self.panels[panel_ix] = panel;
+        self.sizes[panel_ix] = old_size;
+        self.adjust_to_container_size(cx);
+    }
+
+    pub(crate) fn clear(&mut self) {
+        self.panels.clear();
+        self.sizes.clear();
+    }
+
+    #[inline]
+    pub(crate) fn container_size(&self) -> Pixels {
+        self.bounds.size.along(self.axis)
+    }
+
+    pub(crate) fn done_resizing(&mut self, cx: &mut Context<Self>) {
+        self.resizing_panel_ix = None;
+        cx.emit(ResizablePanelEvent::Resized);
+    }
+
+    fn panel_size_range(&self, ix: usize) -> Range<Pixels> {
+        let Some(panel) = self.panels.get(ix) else {
+            return PANEL_MIN_SIZE..Pixels::MAX;
+        };
+
+        panel.size_range.clone()
+    }
+
+    fn sync_real_panel_sizes(&mut self, _: &App) {
+        for (i, panel) in self.panels.iter().enumerate() {
+            self.sizes[i] = panel.bounds.size.along(self.axis);
+        }
+    }
+
+    /// The `ix`` is the index of the panel to resize,
+    /// and the `size` is the new size for the panel.
+    fn resize_panel(&mut self, ix: usize, size: Pixels, _: &mut Window, cx: &mut Context<Self>) {
+        let old_sizes = self.sizes.clone();
+
+        let mut ix = ix;
+        // Only resize the left panels.
+        if ix >= old_sizes.len() - 1 {
+            return;
+        }
+        let container_size = self.container_size();
+        self.sync_real_panel_sizes(cx);
+
+        let move_changed = size - old_sizes[ix];
+        if move_changed == px(0.) {
+            return;
+        }
+
+        let size_range = self.panel_size_range(ix);
+        let new_size = size.clamp(size_range.start, size_range.end);
+        let is_expand = move_changed > px(0.);
+
+        let main_ix = ix;
+        let mut new_sizes = old_sizes.clone();
+
+        if is_expand {
+            let mut changed = new_size - old_sizes[ix];
+            new_sizes[ix] = new_size;
+
+            while changed > px(0.) && ix < old_sizes.len() - 1 {
+                ix += 1;
+                let size_range = self.panel_size_range(ix);
+                let available_size = (new_sizes[ix] - size_range.start).max(px(0.));
+                let to_reduce = changed.min(available_size);
+                new_sizes[ix] -= to_reduce;
+                changed -= to_reduce;
+            }
+        } else {
+            let mut changed = new_size - size;
+            new_sizes[ix] = new_size;
+
+            while changed > px(0.) && ix > 0 {
+                ix -= 1;
+                let size_range = self.panel_size_range(ix);
+                let available_size = (new_sizes[ix] - size_range.start).max(px(0.));
+                let to_reduce = changed.min(available_size);
+                changed -= to_reduce;
+                new_sizes[ix] -= to_reduce;
+            }
+
+            new_sizes[main_ix + 1] += old_sizes[main_ix] - size - changed;
+        }
+
+        let total_size: Pixels = new_sizes.iter().map(|s| s.to_f64()).sum::<f64>().into();
+
+        // If total size exceeds container size, adjust the main panel
+        if total_size > container_size {
+            let overflow = total_size - container_size;
+            new_sizes[main_ix] = (new_sizes[main_ix] - overflow).max(size_range.start);
+        }
+
+        for (i, _) in old_sizes.iter().enumerate() {
+            let size = new_sizes[i];
+            self.panels[i].size = Some(size);
+        }
+        self.sizes = new_sizes;
+        cx.notify();
+    }
+
+    /// Adjust panel sizes according to the container size.
+    ///
+    /// When the container size changes, the panels should take up the same percentage as they did before.
+    fn adjust_to_container_size(&mut self, cx: &mut Context<Self>) {
+        if self.container_size().is_zero() {
+            return;
+        }
+
+        let container_size = self.container_size();
+        let total_size = px(self.sizes.iter().map(f32::from).sum::<f32>());
+
+        for i in 0..self.panels.len() {
+            let size = self.sizes[i];
+            let ratio = size / total_size;
+            let new_size = container_size * ratio;
+
+            self.sizes[i] = new_size;
+            self.panels[i].size = Some(new_size);
+        }
+        cx.notify();
+    }
+}
+
+impl EventEmitter<ResizablePanelEvent> for ResizableState {}
+
+#[derive(Debug, Clone, Default)]
+pub(crate) struct ResizablePanelState {
+    pub size: Option<Pixels>,
+    pub size_range: Range<Pixels>,
+    bounds: Bounds<Pixels>,
+}