Start working on gui

unshell-gui/src/flowchart.rs

@@ -0,0 +1,109 @@
+use egui::Ui;
+use egui::{Color32, Painter, Pos2, Rect, Stroke, UiBuilder, Vec2};
+
+const TARGET_LINE_GAP: f32 = 80.;
+
+const BG_STROKE: Stroke = Stroke {
+    width: 0.3,
+    color: Color32::GRAY,
+};
+
+pub struct FlowChart {
+    // frame: Frame,
+    container: DraggableContainer,
+}
+
+impl FlowChart {
+    pub fn new() -> Self {
+        Self {
+            container: DraggableContainer::new(
+                Pos2 { x: 100., y: 100. },
+                Vec2 { x: 100., y: 100. },
+            ),
+        }
+    }
+
+    fn paint_bg(&self, rect: &Rect, painter: &Painter) {
+        let h_count = (rect.width() / TARGET_LINE_GAP).round() as usize;
+        let h_spacing = rect.width() / h_count as f32;
+        for n in 0..h_count {
+            painter.vline(rect.min.x + n as f32 * h_spacing, rect.y_range(), BG_STROKE);
+        }
+
+        let v_count = (rect.height() / TARGET_LINE_GAP).round() as usize;
+        let v_spacing = rect.height() / v_count as f32;
+        for n in 0..v_count {
+            painter.hline(rect.x_range(), rect.min.y + n as f32 * v_spacing, BG_STROKE);
+        }
+    }
+
+    pub fn paint(&mut self, ui: &mut Ui) {
+        self.paint_bg(&ui.clip_rect(), ui.painter());
+        self.container.show(ui, |ui, rect| {
+            ui.painter().rect(
+                // ui.top
+                *rect,
+                0.,
+                Color32::PURPLE,
+                BG_STROKE,
+                egui::StrokeKind::Middle,
+            );
+            ui.label("Tests");
+            ui.button("Test");
+        })
+    }
+}
+
+pub struct DraggableContainer {
+    pub pos: egui::Pos2,
+    pub size: egui::Vec2,
+    is_dragging: bool,
+    drag_offset: egui::Vec2,
+}
+
+impl DraggableContainer {
+    pub fn new(pos: egui::Pos2, size: egui::Vec2) -> Self {
+        Self {
+            pos,
+            size,
+            is_dragging: false,
+            drag_offset: egui::Vec2::ZERO,
+        }
+    }
+
+    pub fn show<R>(
+        &mut self,
+        ui: &mut egui::Ui,
+        add_contents: impl FnOnce(&mut egui::Ui, &Rect) -> R,
+    ) -> R {
+        let rect = egui::Rect::from_min_size(self.pos, self.size);
+
+        // Handle dragging logic
+        let response = ui.interact(rect, ui.id().with("drag_area"), egui::Sense::drag());
+
+        if response.drag_started() {
+            self.is_dragging = true;
+            if let Some(pointer_pos) = ui.ctx().pointer_interact_pos() {
+                self.drag_offset = self.pos - pointer_pos;
+            }
+        }
+
+        if response.dragged() && self.is_dragging {
+            if let Some(pointer_pos) = ui.ctx().pointer_interact_pos() {
+                self.pos = pointer_pos + self.drag_offset;
+            }
+        }
+
+        if response.drag_stopped() {
+            self.is_dragging = false;
+        }
+
+        // Create a child UI at the specified position
+        // let mut child_ui = ui.child_ui(rect, egui::Layout::top_down(egui::Align::LEFT), None);
+
+        let mut child_ui = ui.new_child(UiBuilder::new().max_rect(rect));
+
+        // Add contents
+        add_contents(&mut child_ui, &rect)
+    }
+}