initial refactor

src/ugui_button.c3

@@ -0,0 +1,48 @@
+module ugui;
+
+// draw a button, return the events on that button
+fn ElemEvents! Ctx.button(&ctx, String label, Rect size)
+{
+	Id id = hash(label);
+
+	Elem *parent = ctx.get_parent()!;
+	Elem *c_elem = ctx.get_elem(id)!;
+	// add it to the tree
+	ctx.tree.add(id, ctx.active_div)!;
+
+	// 1. Fill the element fields
+	// this resets the flags
+	c_elem.type     = ETYPE_BUTTON;
+	Color bg_color = uint_to_rgba(0x0000ffff);
+
+	// if the element is new or the parent was updated then redo layout
+	if (c_elem.flags.is_new || parent.flags.updated) {
+		// 2. Layout
+		c_elem.rect = ctx.position_element(parent, size, true);
+
+		// TODO: 3. Fill the button specific fields
+	}
+
+	// TODO: Check for interactions
+	// FIXME: this is not how normal buttons work, usually focus follows both
+	//        mouse hover and mouse down
+	c_elem.events = ctx.get_elem_events(c_elem);
+	if (parent.flags.has_focus) {
+		if (c_elem.events.mouse_hover) {
+			c_elem.flags.has_focus = true;
+			bg_color = uint_to_rgba(0x00ff00ff);
+		}
+	}
+
+	// Draw the button
+	Cmd cmd = {
+	    .type = CMD_RECT,
+	    .rect =	{
+		    .rect  = c_elem.rect,
+		    .color = bg_color,
+		},
+	};
+	ctx.cmd_queue.enqueue(&cmd)!;
+
+	return c_elem.events;
+}