Optimize completion doc position. (#691)

* optimize completion doc's render

* optimize completion doc's render

* optimize completion doc position

* cargo fmt

* fix panic

* use saturating_sub

* fixs

* fix clippy

* limit completion doc max width 120

1 files changed, 31 insertions, 14 deletions

diff --git a/helix-term/src/ui/completion.rs b/helix-term/src/ui/completion.rs
index 90657764..6c9e3a80 100644
--- a/helix-term/src/ui/completion.rs
+++ b/helix-term/src/ui/completion.rs
@@ -262,8 +262,7 @@ impl Component for Completion {
                 .cursor(doc.text().slice(..));
             let cursor_pos = (helix_core::coords_at_pos(doc.text().slice(..), cursor_pos).row
                 - view.offset.row) as u16;
-
-            let mut doc = match &option.documentation {
+            let mut markdown_doc = match &option.documentation {
                 Some(lsp::Documentation::String(contents))
                 | Some(lsp::Documentation::MarkupContent(lsp::MarkupContent {
                     kind: lsp::MarkupKind::PlainText,
@@ -311,24 +310,42 @@ impl Component for Completion {
                 None => return,
             };
 
-            let half = area.height / 2;
-            let height = 15.min(half);
-            // we want to make sure the cursor is visible (not hidden behind the documentation)
-            let y = if cursor_pos + area.y
-                >= (cx.editor.tree.area().height - height - 2/* statusline + commandline */)
-            {
-                0
+            let (popup_x, popup_y) = self.popup.get_rel_position(area, cx);
+            let (popup_width, _popup_height) = self.popup.get_size();
+            let mut width = area
+                .width
+                .saturating_sub(popup_x)
+                .saturating_sub(popup_width);
+            let area = if width > 30 {
+                let mut height = area.height.saturating_sub(popup_y);
+                let x = popup_x + popup_width;
+                let y = popup_y;
+
+                if let Some((rel_width, rel_height)) = markdown_doc.required_size((width, height)) {
+                    width = rel_width;
+                    height = rel_height;
+                }
+                Rect::new(x, y, width, height)
             } else {
-                // -2 to subtract command line + statusline. a bit of a hack, because of splits.
-                area.height.saturating_sub(height).saturating_sub(2)
-            };
+                let half = area.height / 2;
+                let height = 15.min(half);
+                // we want to make sure the cursor is visible (not hidden behind the documentation)
+                let y = if cursor_pos + area.y
+                    >= (cx.editor.tree.area().height - height - 2/* statusline + commandline */)
+                {
+                    0
+                } else {
+                    // -2 to subtract command line + statusline. a bit of a hack, because of splits.
+                    area.height.saturating_sub(height).saturating_sub(2)
+                };
 
-            let area = Rect::new(0, y, area.width, height);
+                Rect::new(0, y, area.width, height)
+            };
 
             // clear area
             let background = cx.editor.theme.get("ui.popup");
             surface.clear_with(area, background);
-            doc.render(area, surface, cx);
+            markdown_doc.render(area, surface, cx);
         }
     }
 }