| 🛟 Updated. 28d5985 k33g 17h ago | 1 | package terminal |
| 2 | |
| 3 | import ( |
| 4 | "github.com/gdamore/tcell/v2" |
| 5 | |
| 6 | "codeberg.org/turbo-editors/turbo-core/theme" |
| 7 | "codeberg.org/turbo-editors/turbo-core/ui" |
| 8 | ) |
| 9 | |
| 10 | // Draw paints the terminal's grid. |
| 11 | func (v *View) Draw(p *ui.Painter, th *theme.Theme) { |
| 12 | v.mu.Lock() |
| 13 | defer v.mu.Unlock() |
| 14 | |
| 15 | area := p.Size() |
| 16 | base := th.Style(theme.KeyTerminalText) |
| 17 | p.Fill(area, ' ', base) |
| 18 | |
| 19 | for row := range area.H { |
| 20 | v.drawLine(p, v.lineAt(row), row, area.W, base) |
| 21 | } |
| 22 | v.drawCursor(p, th) |
| 23 | } |
| 24 | |
| 25 | // drawLine paints one row of the grid. |
| 26 | func (v *View) drawLine(p *ui.Painter, line Line, row, width int, base tcell.Style) { |
| 27 | for col, cell := range line { |
| 28 | if col >= width { |
| 29 | return |
| 30 | } |
| 31 | p.SetCell(col, row, cell.Rune, resolve(cell.Style, base)) |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | // resolve fills a cell's unset colours in from the theme. |
| 36 | // |
| 37 | // A program that has said nothing about colour gets the theme's, which is what |
| 38 | // lets a terminal window look like the rest of the editor instead of like the |
| 39 | // terminal's own defaults. |
| 40 | func resolve(style, base tcell.Style) tcell.Style { |
| 41 | foreground, background, _ := style.Decompose() |
| 42 | baseForeground, baseBackground, _ := base.Decompose() |
| 43 | |
| 44 | if foreground == tcell.ColorDefault { |
| 45 | style = style.Foreground(baseForeground) |
| 46 | } |
| 47 | if background == tcell.ColorDefault { |
| 48 | style = style.Background(baseBackground) |
| 49 | } |
| 50 | return style |
| 51 | } |
| 52 | |
| 53 | // drawCursor marks where the shell's cursor is. |
| 54 | // |
| 55 | // It is drawn only on the live screen: a cursor shown while the user is |
| 56 | // reading back through the history would point at a line the shell is not |
| 57 | // writing to. |
| 58 | func (v *View) drawCursor(p *ui.Painter, th *theme.Theme) { |
| 59 | screen := v.parser.Screen() |
| 60 | if v.scrollOffset != 0 || !screen.CursorVisible() || !v.Focused() { |
| 61 | return |
| 62 | } |
| 63 | |
| 64 | cursor := screen.Cursor() |
| 65 | character, _ := p.CellAt(cursor.Col, cursor.Row) |
| 66 | p.SetCell(cursor.Col, cursor.Row, character, th.Style(theme.KeyTerminalCursor)) |
| 67 | p.ShowCursor(cursor.Col, cursor.Row) |
| 68 | } |
| 69 | |
| 70 | // lineAt returns the line to show on a visible row, which comes from the |
| 71 | // history when the view has been scrolled back. |
| 72 | // |
| 73 | // It must be called with the lock held. |
| 74 | func (v *View) lineAt(row int) Line { |
| 75 | screen := v.parser.Screen() |
| 76 | index := screen.ScrollbackLen() - v.scrollOffset + row |
| 77 | |
| 78 | if index < screen.ScrollbackLen() { |
| 79 | return screen.ScrollbackLine(index) |
| 80 | } |
| 81 | return screen.Line(index - screen.ScrollbackLen()) |
| 82 | } |
| 83 | |
| 84 | // ScrollOffset returns how many lines back into the history the view is |
| 85 | // looking. Zero is the live screen. |
| 86 | func (v *View) ScrollOffset() int { |
| 87 | v.mu.Lock() |
| 88 | defer v.mu.Unlock() |
| 89 | return v.scrollOffset |
| 90 | } |
| 91 | |
| 92 | // ScrollBy moves the view back through the history, or forwards towards the |
| 93 | // live screen with a negative count. It stops at either end. |
| 94 | func (v *View) ScrollBy(lines int) { |
| 95 | v.mu.Lock() |
| 96 | defer v.mu.Unlock() |
| 97 | |
| 98 | v.scrollOffset = min(max(v.scrollOffset+lines, 0), v.parser.Screen().ScrollbackLen()) |
| 99 | } |
| 100 | |
| 101 | // ScrollToBottom goes back to the live screen, which is where any key press |
| 102 | // puts the view. |
| 103 | func (v *View) ScrollToBottom() { |
| 104 | v.mu.Lock() |
| 105 | defer v.mu.Unlock() |
| 106 | v.scrollOffset = 0 |
| 107 | } |