Add blocks as basis for rendering

src/ui.rs

@@ -1,4 +1,5 @@
 mod chat;
+mod chat2;
 mod euph;
 mod input;
 mod rooms;

src/ui/chat2.rs

@@ -0,0 +1 @@
+mod blocks;

src/ui/chat2/blocks.rs

@@ -0,0 +1,223 @@
+//! Common rendering logic.
+
+use std::collections::{vec_deque, VecDeque};
+
+use toss::widgets::Predrawn;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Range<T> {
+    pub top: T,
+    pub bottom: T,
+}
+
+impl<T> Range<T> {
+    pub fn new(top: T, bottom: T) -> Self {
+        Self { top, bottom }
+    }
+}
+
+impl Range<i32> {
+    pub fn shifted(self, delta: i32) -> Self {
+        Self::new(self.top + delta, self.bottom + delta)
+    }
+
+    pub fn with_top(self, top: i32) -> Self {
+        self.shifted(top - self.top)
+    }
+
+    pub fn with_bottom(self, bottom: i32) -> Self {
+        self.shifted(bottom - self.bottom)
+    }
+}
+
+pub struct Block<Id> {
+    id: Id,
+    widget: Predrawn,
+    focus: Range<i32>,
+    can_be_cursor: bool,
+}
+
+impl<Id> Block<Id> {
+    pub fn new(id: Id, widget: Predrawn, can_be_cursor: bool) -> Self {
+        let height: i32 = widget.size().height.into();
+        Self {
+            id,
+            widget,
+            focus: Range::new(0, height),
+            can_be_cursor,
+        }
+    }
+
+    pub fn id(&self) -> &Id {
+        &self.id
+    }
+
+    pub fn into_widget(self) -> Predrawn {
+        self.widget
+    }
+
+    fn height(&self) -> i32 {
+        self.widget.size().height.into()
+    }
+
+    pub fn set_focus(&mut self, focus: Range<i32>) {
+        assert!(0 <= focus.top);
+        assert!(focus.top <= focus.bottom);
+        assert!(focus.bottom <= self.height());
+        self.focus = focus;
+    }
+
+    pub fn focus(&self, range: Range<i32>) -> Range<i32> {
+        Range::new(range.top + self.focus.top, range.top + self.focus.bottom)
+    }
+
+    pub fn can_be_cursor(&self) -> bool {
+        self.can_be_cursor
+    }
+}
+
+pub struct Blocks<Id> {
+    blocks: VecDeque<Block<Id>>,
+    range: Range<i32>,
+    end: Range<bool>,
+}
+
+impl<Id> Blocks<Id> {
+    pub fn new(at: i32) -> Self {
+        Self {
+            blocks: VecDeque::new(),
+            range: Range::new(at, at),
+            end: Range::new(false, false),
+        }
+    }
+
+    pub fn range(&self) -> Range<i32> {
+        self.range
+    }
+
+    pub fn end(&self) -> Range<bool> {
+        self.end
+    }
+
+    pub fn iter(&self) -> Iter<'_, Id> {
+        Iter {
+            iter: self.blocks.iter(),
+            range: self.range,
+        }
+    }
+
+    pub fn into_iter(self) -> IntoIter<Id> {
+        IntoIter {
+            iter: self.blocks.into_iter(),
+            range: self.range,
+        }
+    }
+
+    // TODO Remove index from search result
+    pub fn find_block(&self, id: &Id) -> Option<(Range<i32>, &Block<Id>)>
+    where
+        Id: Eq,
+    {
+        self.iter().find(|(_, block)| block.id == *id)
+    }
+
+    pub fn push_top(&mut self, block: Block<Id>) {
+        assert!(!self.end.top);
+        self.range.top -= block.height();
+        self.blocks.push_front(block);
+    }
+
+    pub fn push_bottom(&mut self, block: Block<Id>) {
+        assert!(!self.end.bottom);
+        self.range.bottom += block.height();
+        self.blocks.push_back(block);
+    }
+
+    pub fn append_top(&mut self, other: Self) {
+        assert!(!self.end.top);
+        assert!(!other.end.bottom);
+        for block in other.blocks.into_iter().rev() {
+            self.push_top(block);
+        }
+        self.end.top = other.end.top;
+    }
+
+    pub fn append_bottom(&mut self, other: Self) {
+        assert!(!self.end.bottom);
+        assert!(!other.end.top);
+        for block in other.blocks {
+            self.push_bottom(block);
+        }
+        self.end.bottom = other.end.bottom;
+    }
+
+    pub fn end_top(&mut self) {
+        self.end.top = true;
+    }
+
+    pub fn end_bottom(&mut self) {
+        self.end.bottom = true;
+    }
+
+    pub fn shift(&mut self, delta: i32) {
+        self.range = self.range.shifted(delta);
+    }
+
+    pub fn set_top(&mut self, top: i32) {
+        self.shift(top - self.range.top);
+    }
+
+    pub fn set_bottom(&mut self, bottom: i32) {
+        self.shift(bottom - self.range.bottom);
+    }
+}
+
+pub struct Iter<'a, Id> {
+    iter: vec_deque::Iter<'a, Block<Id>>,
+    range: Range<i32>,
+}
+
+impl<'a, Id> Iterator for Iter<'a, Id> {
+    type Item = (Range<i32>, &'a Block<Id>);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let block = self.iter.next()?;
+        let range = Range::new(self.range.top, self.range.top + block.height());
+        self.range.top = range.bottom;
+        Some((range, block))
+    }
+}
+
+impl<Id> DoubleEndedIterator for Iter<'_, Id> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        let block = self.iter.next_back()?;
+        let range = Range::new(self.range.bottom - block.height(), self.range.bottom);
+        self.range.bottom = range.top;
+        Some((range, block))
+    }
+}
+
+pub struct IntoIter<Id> {
+    iter: vec_deque::IntoIter<Block<Id>>,
+    range: Range<i32>,
+}
+
+impl<Id> Iterator for IntoIter<Id> {
+    type Item = (Range<i32>, Block<Id>);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let block = self.iter.next()?;
+        let range = Range::new(self.range.top, self.range.top + block.height());
+        self.range.top = range.bottom;
+        Some((range, block))
+    }
+}
+
+impl<Id> DoubleEndedIterator for IntoIter<Id> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        let block = self.iter.next_back()?;
+        let range = Range::new(self.range.bottom - block.height(), self.range.bottom);
+        self.range.bottom = range.top;
+        Some((range, block))
+    }
+}