Ensure blocks are always scrolled properly

This commit is contained in:
Joscha 2022-06-14 19:37:04 +02:00
parent ea6b345fa9
commit 704873af6e
2 changed files with 66 additions and 26 deletions

View file

@ -166,6 +166,14 @@ impl<I: PartialEq> Blocks<I> {
}
}
pub fn offset(&mut self, delta: i32) {
self.top_line += delta;
self.bottom_line += delta;
for block in &mut self.blocks {
block.line += delta;
}
}
pub fn find(&self, id: &I) -> Option<&Block<I>> {
self.blocks.iter().find(|b| &b.id == id)
}

View file

@ -59,13 +59,18 @@ impl<M: Msg> TreeView<M> {
frame: &mut Frame,
size: Size,
blocks: &mut Blocks<M::Id>,
mut tree_id: M::Id,
tree_id: &mut Option<M::Id>,
) {
while blocks.top_line > 0 {
let tree = store.tree(room, &tree_id).await;
blocks.prepend(layout_tree(frame, size, tree));
if let Some(prev_tree_id) = store.prev_tree(room, &tree_id).await {
tree_id = prev_tree_id;
*tree_id = if let Some(tree_id) = tree_id {
store.prev_tree(room, tree_id).await
} else {
break;
};
if let Some(tree_id) = tree_id {
let tree = store.tree(room, tree_id).await;
blocks.prepend(layout_tree(frame, size, tree));
} else {
break;
}
@ -78,13 +83,18 @@ impl<M: Msg> TreeView<M> {
frame: &mut Frame,
size: Size,
blocks: &mut Blocks<M::Id>,
mut tree_id: M::Id,
tree_id: &mut Option<M::Id>,
) {
while blocks.bottom_line < size.height as i32 {
let tree = store.tree(room, &tree_id).await;
blocks.append(layout_tree(frame, size, tree));
if let Some(next_tree_id) = store.next_tree(room, &tree_id).await {
tree_id = next_tree_id;
*tree_id = if let Some(tree_id) = tree_id {
store.next_tree(room, tree_id).await
} else {
break;
};
if let Some(tree_id) = tree_id {
let tree = store.tree(room, tree_id).await;
blocks.append(layout_tree(frame, size, tree));
} else {
break;
}
@ -104,36 +114,58 @@ impl<M: Msg> TreeView<M> {
// TODO Ensure focus lies on cursor path, otherwise unfocus
// TODO Unfold all messages on path to cursor
// Layout cursor subtree (with correct offsets)
// Layout cursor subtree (with correct offsets based on cursor)
let cursor_path = store.path(room, &cursor.id).await;
let cursor_tree_id = cursor_path.first();
let cursor_tree = store.tree(room, cursor_tree_id).await;
let mut layout = layout_tree(frame, size, cursor_tree);
layout.calculate_offsets_with_cursor(cursor, size.height);
let mut blocks = layout_tree(frame, size, cursor_tree);
blocks.calculate_offsets_with_cursor(cursor, size.height);
// Expand upwards and downwards
// TODO Ensure that blocks are scrolled correctly
// TODO Don't do this if there is a focus
if let Some(prev_tree) = store.prev_tree(room, cursor_tree_id).await {
Self::expand_blocks_up(room, store, frame, size, &mut layout, prev_tree).await;
// Expand upwards and downwards, ensuring the blocks are not
// scrolled too far in any direction.
//
// If the blocks fill the screen, scrolling stops when the topmost
// message is at the top of the screen or the bottommost message is
// at the bottom. If they don't fill the screen, the bottommost
// message should always be at the bottom.
//
// Because our helper functions always expand the blocks until they
// reach the top or bottom of the screen, we can determine that
// we're at the top/bottom if expansion stopped anywhere in the
// middle of the screen.
//
// TODO Don't expand if there is a focus
let mut top_tree_id = Some(cursor_tree_id.clone());
Self::expand_blocks_up(room, store, frame, size, &mut blocks, &mut top_tree_id).await;
if blocks.top_line > 0 {
blocks.offset(-blocks.top_line);
}
if let Some(next_tree) = store.next_tree(room, cursor_tree_id).await {
Self::expand_blocks_down(room, store, frame, size, &mut layout, next_tree).await;
let mut bot_tree_id = Some(cursor_tree_id.clone());
Self::expand_blocks_down(room, store, frame, size, &mut blocks, &mut bot_tree_id).await;
if blocks.bottom_line < size.height as i32 - 1 {
blocks.offset(size.height as i32 - 1 - blocks.bottom_line);
}
// If we only moved the blocks down, we need to expand upwards again
// to make sure we fill the screen.
Self::expand_blocks_up(room, store, frame, size, &mut blocks, &mut top_tree_id).await;
layout
blocks
} else {
// TODO Ensure there is no focus
// Start at the bottom of the screen
let mut layout = Blocks::new_below(size.height as i32 - 1);
let mut blocks = Blocks::new_below(size.height as i32 - 1);
// Expand upwards until the edge of the screen
if let Some(last_tree) = store.last_tree(room).await {
Self::expand_blocks_up(room, store, frame, size, &mut layout, last_tree).await;
// Expand upwards from last tree
if let Some(last_tree_id) = store.last_tree(room).await {
let last_tree = store.tree(room, &last_tree_id).await;
blocks.prepend(layout_tree(frame, size, last_tree));
let mut tree_id = Some(last_tree_id);
Self::expand_blocks_up(room, store, frame, size, &mut blocks, &mut tree_id).await;
}
layout
blocks
}
}
}