| 🛟 Updated. 28d5985 k33g 5h ago | 1 | package filetree |
| 2 | |
| 3 | import ( |
| 4 | "strings" |
| 5 | |
| 6 | "github.com/gdamore/tcell/v2" |
| 7 | |
| 8 | "codeberg.org/turbo-editors/turbo-core/theme" |
| 9 | "codeberg.org/turbo-editors/turbo-core/ui" |
| 10 | ) |
| 11 | |
| 12 | // Draw paints the visible rows and the scroll bar beside them. |
| 13 | func (v *View) Draw(p *ui.Painter, th *theme.Theme) { |
| 14 | area := p.Sub(v.Bounds()) |
| 15 | area.Clear(th.Style(theme.KeyTreeText)) |
| 16 | |
| 17 | rows := v.tree.Rows() |
| 18 | v.scrollToSelection(len(rows), area.Size().H) |
| 19 | width := max(area.Size().W-1, 0) |
| 20 | |
| 21 | for line := range area.Size().H { |
| 22 | index := v.top + line |
| 23 | if index >= len(rows) { |
| 24 | break |
| 25 | } |
| 26 | v.drawRow(area, line, width, rows[index], index == v.selected, th) |
| 27 | } |
| 28 | |
| 29 | ui.DrawVScrollBar(area, area.Size().W-1, 0, area.Size().H, |
| 30 | v.top, area.Size().H, len(rows), |
| 31 | th.Style(theme.KeyScrollBar), th.Style(theme.KeyScrollBarThumb)) |
| 32 | } |
| 33 | |
| 34 | // drawRow paints one entry: its indentation, its marker and its name. |
| 35 | func (v *View) drawRow(p *ui.Painter, line, width int, row Row, selected bool, th *theme.Theme) { |
| 36 | style := v.styleFor(row.Node, selected, th) |
| 37 | if selected { |
| 38 | p.HLine(0, line, width, ' ', style) |
| 39 | } |
| 40 | p.TextLimited(0, line, width, label(row), style) |
| 41 | } |
| 42 | |
| 43 | // label renders one row as the text to draw. |
| 44 | // |
| 45 | // A file is indented by a marker's width as well, so that names line up in a |
| 46 | // column whatever their neighbours are. |
| 47 | func label(row Row) string { |
| 48 | return strings.Repeat(indent, row.Depth) + marker(row.Node) + row.Node.Name() |
| 49 | } |
| 50 | |
| 51 | // marker returns the glyph that says whether a directory is open, closed, or |
| 52 | // not a directory at all. |
| 53 | func marker(node *Node) string { |
| 54 | switch { |
| 55 | case !node.IsDir(): |
| 56 | return fileMarker |
| 57 | case node.Expanded(): |
| 58 | return openMarker |
| 59 | default: |
| 60 | return closedMarker |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | // styleFor picks the colour of one row. |
| 65 | // |
| 66 | // The highlight is dimmed when the tree does not have the focus, the same way |
| 67 | // a list box dims its own, so that a screenful of windows still says where the |
| 68 | // keyboard is. |
| 69 | func (v *View) styleFor(node *Node, selected bool, th *theme.Theme) tcell.Style { |
| 70 | switch { |
| 71 | case selected && v.Focused(): |
| 72 | return th.Style(theme.KeyTreeSelected) |
| 73 | case selected: |
| 74 | return th.Style(theme.KeyTreeUnfocused) |
| 75 | case node.IsDir(): |
| 76 | return th.Style(theme.KeyTreeDirectory) |
| 77 | default: |
| 78 | return th.Style(theme.KeyTreeText) |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | // scrollToSelection moves the window of visible rows just enough to keep the |
| 83 | // highlight on screen. |
| 84 | func (v *View) scrollToSelection(total, height int) { |
| 85 | if height <= 0 { |
| 86 | return |
| 87 | } |
| 88 | if v.selected < v.top { |
| 89 | v.top = v.selected |
| 90 | } |
| 91 | if v.selected >= v.top+height { |
| 92 | v.top = v.selected - height + 1 |
| 93 | } |
| 94 | v.top = min(max(v.top, 0), max(total-height, 0)) |
| 95 | } |