| 1 | //! Ellipse tool - draw circles and ellipses. |
| 2 | |
| 3 | use super::Tool; |
| 4 | use crate::annotate::state::ToolProperties; |
| 5 | use gartk_core::{InputEvent, MouseButton, Point}; |
| 6 | use gartk_render::cairo::Context; |
| 7 | use gartk_render::set_color; |
| 8 | use gartk_x11::CursorShape; |
| 9 | use std::f64::consts::PI; |
| 10 | |
| 11 | /// Ellipse drawing tool. |
| 12 | pub struct EllipseTool { |
| 13 | /// Center or first corner of bounding box. |
| 14 | start: Option<Point>, |
| 15 | /// Edge point or opposite corner. |
| 16 | end: Option<Point>, |
| 17 | /// Whether we're currently drawing. |
| 18 | drawing: bool, |
| 19 | } |
| 20 | |
| 21 | impl EllipseTool { |
| 22 | /// Create a new ellipse tool. |
| 23 | pub fn new() -> Self { |
| 24 | Self { |
| 25 | start: None, |
| 26 | end: None, |
| 27 | drawing: false, |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | /// Calculate ellipse parameters from start and end points. |
| 32 | /// Returns (center_x, center_y, radius_x, radius_y). |
| 33 | fn calculate_ellipse(&self) -> Option<(f64, f64, f64, f64)> { |
| 34 | let (start, end) = (self.start?, self.end?); |
| 35 | |
| 36 | // Bounding box mode: start and end are opposite corners |
| 37 | let cx = (start.x + end.x) as f64 / 2.0; |
| 38 | let cy = (start.y + end.y) as f64 / 2.0; |
| 39 | let rx = ((end.x - start.x) as f64 / 2.0).abs(); |
| 40 | let ry = ((end.y - start.y) as f64 / 2.0).abs(); |
| 41 | |
| 42 | if rx > 0.0 && ry > 0.0 { |
| 43 | Some((cx, cy, rx, ry)) |
| 44 | } else { |
| 45 | None |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | /// Draw an ellipse using Cairo. |
| 50 | fn draw_ellipse(&self, ctx: &Context, props: &ToolProperties) { |
| 51 | if let Some((cx, cy, rx, ry)) = self.calculate_ellipse() { |
| 52 | // Use scaling to draw ellipse from circle |
| 53 | ctx.save().ok(); |
| 54 | ctx.translate(cx, cy); |
| 55 | ctx.scale(rx, ry); |
| 56 | |
| 57 | ctx.new_path(); |
| 58 | ctx.arc(0.0, 0.0, 1.0, 0.0, 2.0 * PI); |
| 59 | |
| 60 | ctx.restore().ok(); |
| 61 | |
| 62 | set_color(ctx, props.color); |
| 63 | |
| 64 | if props.fill { |
| 65 | let _ = ctx.fill(); |
| 66 | } else { |
| 67 | // Scale line width to maintain consistent appearance |
| 68 | ctx.set_line_width(props.line_width); |
| 69 | let _ = ctx.stroke(); |
| 70 | } |
| 71 | } |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | impl Default for EllipseTool { |
| 76 | fn default() -> Self { |
| 77 | Self::new() |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | impl Tool for EllipseTool { |
| 82 | fn handle_event(&mut self, event: &InputEvent, _props: &ToolProperties) -> bool { |
| 83 | match event { |
| 84 | InputEvent::MousePress(e) if e.button == Some(MouseButton::Left) => { |
| 85 | self.start = Some(e.position); |
| 86 | self.end = Some(e.position); |
| 87 | self.drawing = true; |
| 88 | true |
| 89 | } |
| 90 | InputEvent::MouseMove(e) if self.drawing => { |
| 91 | self.end = Some(e.position); |
| 92 | true |
| 93 | } |
| 94 | InputEvent::MouseRelease(e) if e.button == Some(MouseButton::Left) && self.drawing => { |
| 95 | self.end = Some(e.position); |
| 96 | self.drawing = false; |
| 97 | true |
| 98 | } |
| 99 | _ => false, |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | fn draw_preview(&self, ctx: &Context, props: &ToolProperties) { |
| 104 | self.draw_ellipse(ctx, props); |
| 105 | } |
| 106 | |
| 107 | fn commit(&self, ctx: &Context, props: &ToolProperties) { |
| 108 | self.draw_ellipse(ctx, props); |
| 109 | } |
| 110 | |
| 111 | fn reset(&mut self) { |
| 112 | self.start = None; |
| 113 | self.end = None; |
| 114 | self.drawing = false; |
| 115 | } |
| 116 | |
| 117 | fn cursor(&self) -> CursorShape { |
| 118 | CursorShape::Crosshair |
| 119 | } |
| 120 | |
| 121 | fn is_drawing(&self) -> bool { |
| 122 | self.drawing |
| 123 | } |
| 124 | |
| 125 | fn can_commit(&self) -> bool { |
| 126 | self.calculate_ellipse().is_some() |
| 127 | } |
| 128 | } |
| 129 |