Add flex resize, focus mode, hard-coded limits for now (clone of #2704)

helix-term/src/commands.rs

@@ -45,7 +45,7 @@ use helix_view::{
     input::KeyEvent,
     keyboard::KeyCode,
     theme::Style,
-    tree,
+    tree::{self, Dimension, Resize},
     view::View,
     Document, DocumentId, Editor, ViewId,
 };
@@ -382,6 +382,11 @@ impl MappableCommand {
         goto_prev_change, "Goto previous change",
         goto_first_change, "Goto first change",
         goto_last_change, "Goto last change",
+        grow_buffer_width, "Grow focused container width",
+        shrink_buffer_width, "Shrink focused container width",
+        grow_buffer_height, "Grow focused container height",
+        shrink_buffer_height, "Shrink focused container height",
+        toggle_focus_window, "Toggle focus mode on buffer",
         goto_line_start, "Goto line start",
         goto_line_end, "Goto line end",
         goto_next_buffer, "Goto next buffer",
@@ -807,6 +812,25 @@ fn goto_line_start(cx: &mut Context) {
     )
 }
 
+fn grow_buffer_width(cx: &mut Context) {
+    cx.editor.resize_buffer(Resize::Grow, Dimension::Width);
+}
+
+fn shrink_buffer_width(cx: &mut Context) {
+    cx.editor.resize_buffer(Resize::Shrink, Dimension::Width);
+}
+fn grow_buffer_height(cx: &mut Context) {
+    cx.editor.resize_buffer(Resize::Grow, Dimension::Height);
+}
+
+fn shrink_buffer_height(cx: &mut Context) {
+    cx.editor.resize_buffer(Resize::Shrink, Dimension::Height);
+}
+
+fn toggle_focus_window(cx: &mut Context) {
+    cx.editor.toggle_focus_window();
+}
+
 fn goto_next_buffer(cx: &mut Context) {
     goto_buffer(cx.editor, Direction::Forward, cx.count());
 }

helix-term/src/keymap/default.rs

@@ -26,6 +26,22 @@ pub fn default() -> HashMap<Mode, KeyTrie> {
         "home" => goto_line_start,
         "end" => goto_line_end,
 
+        "A-w" => { "Alter Window"
+            "A-h"|"A-left" |"h"|"left" => shrink_buffer_width,
+            "A-l"|"A-right"|"l"|"right" => grow_buffer_width,
+            "A-j"|"A-down" |"j"|"down" => shrink_buffer_height,
+            "A-k"|"A-up"   |"k"|"up" => grow_buffer_height,
+            "A-f"|"f" => toggle_focus_window,
+        },
+
+        "A-W" => { "Alter Window" sticky=true
+            "h"|"left" => shrink_buffer_width,
+            "l"|"right" => grow_buffer_width,
+            "j"|"down" => shrink_buffer_height,
+            "k"|"up" => grow_buffer_height,
+            "f" => toggle_focus_window,
+        },
+
         "w" => move_next_word_start,
         "b" => move_prev_word_start,
         "e" => move_next_word_end,

helix-view/src/editor.rs

@@ -9,7 +9,7 @@ use crate::{
     input::KeyEvent,
     register::Registers,
     theme::{self, Theme},
-    tree::{self, Tree},
+    tree::{self, Dimension, Resize, Tree},
     Document, DocumentId, View, ViewId,
 };
 use dap::StackFrame;
@@ -1897,6 +1897,14 @@ impl Editor {
         self.tree.transpose();
     }
 
+    pub fn resize_buffer(&mut self, resize_type: Resize, dimension: Dimension) {
+        self.tree.resize_buffer(resize_type, dimension);
+    }
+
+    pub fn toggle_focus_window(&mut self) {
+        self.tree.toggle_focus_window();
+    }
+
     pub fn should_close(&self) -> bool {
         self.tree.is_empty()
     }

helix-view/src/tree.rs

@@ -29,6 +29,16 @@ pub enum Content {
     Container(Box<Container>),
 }
 
+pub enum Resize {
+    Shrink,
+    Grow,
+}
+
+pub enum Dimension {
+    Width,
+    Height,
+}
+
 impl Node {
     pub fn container(layout: Layout) -> Self {
         Self {
@@ -65,6 +75,14 @@ pub struct Container {
     layout: Layout,
     children: Vec<ViewId>,
     area: Rect,
+    node_bounds: Vec<ContainerBounds>,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct ContainerBounds {
+    width: usize,
+    height: usize,
+    expand: bool,
 }
 
 impl Container {
@@ -73,8 +91,69 @@ impl Container {
             layout,
             children: Vec::new(),
             area: Rect::default(),
+            node_bounds: Vec::new(),
         }
     }
+
+    fn get_child_by_view_id(&mut self, node: ViewId) -> Option<&mut ContainerBounds> {
+        self.children
+            .iter()
+            .position(|child| child == &node)
+            .and_then(|index| self.node_bounds.get_mut(index))
+    }
+
+    fn push_child(&mut self, node: ViewId) -> &mut Self {
+        self.children.push(node);
+        self.add_child_bounds();
+        self
+    }
+
+    fn insert_child(&mut self, index: usize, node: ViewId) -> &mut Self {
+        self.children.insert(index, node);
+        self.insert_child_bounds(index);
+        self
+    }
+
+    fn add_child_bounds(&mut self) -> &mut Self {
+        self.node_bounds.push(ContainerBounds {
+            width: 10,
+            height: 10,
+            expand: false,
+        });
+        self
+    }
+
+    fn insert_child_bounds(&mut self, index: usize) -> &mut Self {
+        self.node_bounds.insert(
+            index,
+            ContainerBounds {
+                width: 10,
+                height: 10,
+                expand: false,
+            },
+        );
+        self
+    }
+
+    fn calculate_slots_width(&self) -> usize {
+        self.node_bounds
+            .iter()
+            .map(|bounds| match bounds.expand {
+                true => 40,
+                false => bounds.width,
+            })
+            .sum()
+    }
+
+    fn calculate_slots_height(&self) -> usize {
+        self.node_bounds
+            .iter()
+            .map(|bounds| match bounds.expand {
+                true => 40,
+                false => bounds.height,
+            })
+            .sum()
+    }
 }
 
 impl Default for Container {
@@ -131,7 +210,7 @@ impl Tree {
             pos + 1
         };
 
-        container.children.insert(pos, node);
+        container.insert_child(pos, node);
         // focus the new node
         self.focus = node;
 
@@ -168,7 +247,7 @@ impl Tree {
                     .unwrap();
                 pos + 1
             };
-            container.children.insert(pos, node);
+            container.insert_child(pos, node);
             self.nodes[node].parent = parent;
         } else {
             let mut split = Node::container(layout);
@@ -182,8 +261,8 @@ impl Tree {
                 } => container,
                 _ => unreachable!(),
             };
-            container.children.push(focus);
-            container.children.push(node);
+            container.push_child(focus);
+            container.push_child(node);
             self.nodes[focus].parent = split;
             self.nodes[node].parent = split;
 
@@ -382,12 +461,17 @@ impl Tree {
                     match container.layout {
                         Layout::Horizontal => {
                             let len = container.children.len();
-
-                            let height = area.height / len as u16;
-
+                            let slots = container.calculate_slots_height();
+                            let slot_height = area.height as f32 / slots as f32;
                             let mut child_y = area.y;
 
                             for (i, child) in container.children.iter().enumerate() {
+                                let bounds = container.node_bounds[i];
+                                let height = match bounds.expand {
+                                    true => (40.0 * slot_height) as u16,
+                                    false => (slot_height * bounds.height as f32).floor() as u16,
+                                };
+
                                 let mut area = Rect::new(
                                     container.area.x,
                                     child_y,
@@ -396,7 +480,7 @@ impl Tree {
                                 );
                                 child_y += height;
 
-                                // last child takes the remaining width because we can get uneven
+                                // last child takes the remaining height because we can get uneven
                                 // space from rounding
                                 if i == len - 1 {
                                     area.height = container.area.y + container.area.height - area.y;
@@ -413,11 +497,19 @@ impl Tree {
                             let total_gap = inner_gap * len_u16.saturating_sub(2);
 
                             let used_area = area.width.saturating_sub(total_gap);
-                            let width = used_area / len_u16;
+
+                            let slots = container.calculate_slots_width();
+                            let slot_width: f32 = used_area as f32 / slots as f32;
 
                             let mut child_x = area.x;
 
                             for (i, child) in container.children.iter().enumerate() {
+                                let bounds = container.node_bounds[i];
+                                let width = match bounds.expand {
+                                    true => (40.0 * slot_width) as u16,
+                                    false => (slot_width * bounds.width as f32).floor() as u16,
+                                };
+
                                 let mut area = Rect::new(
                                     child_x,
                                     container.area.y,
@@ -596,6 +688,83 @@ impl Tree {
         }
     }
 
+    fn get_active_node_bounds_mut(
+        &mut self,
+        expect_layout: Layout,
+    ) -> Option<&mut ContainerBounds> {
+        let mut focus = self.focus;
+        let mut parent = self.nodes[focus].parent;
+
+        // Parent expected to be container
+        if let Some(focused_layout) = match &self.nodes[parent].content {
+            Content::View(_) => unreachable!(),
+            Content::Container(node) => Some(node.layout),
+        } {
+            // if we want to make a width change and we have a `Horizontal` layout focused,
+            // alter the parent `Vertical` layout instead and vice versa
+            if focused_layout != expect_layout {
+                focus = parent;
+                parent = self.nodes[parent].parent;
+            }
+
+            if let Content::Container(node) = &mut self.nodes[parent].content {
+                return node.as_mut().get_child_by_view_id(focus);
+            };
+        }
+        None
+    }
+
+    pub fn resize_buffer(&mut self, resize_type: Resize, dimension: Dimension) {
+        match dimension {
+            Dimension::Width => {
+                if let Some(bounds) = self.get_active_node_bounds_mut(Layout::Vertical) {
+                    match resize_type {
+                        Resize::Shrink => {
+                            if bounds.width > 1 {
+                                bounds.width -= 1;
+                            }
+                        }
+                        Resize::Grow => {
+                            if bounds.width < 20 {
+                                bounds.width += 1;
+                            }
+                        }
+                    };
+                    self.recalculate();
+                }
+            }
+            Dimension::Height => {
+                if let Some(bounds) = self.get_active_node_bounds_mut(Layout::Horizontal) {
+                    match resize_type {
+                        Resize::Shrink => {
+                            if bounds.height > 1 {
+                                bounds.height -= 1;
+                            }
+                        }
+                        Resize::Grow => {
+                            if bounds.height < 20 {
+                                bounds.height += 1;
+                            }
+                        }
+                    };
+                    self.recalculate();
+                }
+            }
+        }
+    }
+
+    pub fn toggle_focus_window(&mut self) {
+        if let Some(bounds) = self.get_active_node_bounds_mut(Layout::Horizontal) {
+            bounds.expand = !bounds.expand;
+        }
+
+        if let Some(bounds) = self.get_active_node_bounds_mut(Layout::Vertical) {
+            bounds.expand = !bounds.expand;
+        }
+
+        self.recalculate();
+    }
+
     pub fn swap_split_in_direction(&mut self, direction: Direction) -> Option<()> {
         let focus = self.focus;
         let target = self.find_split_in_direction(focus, direction)?;