#include "xorrectangle.h"

#include <gtk/gtk.h>

bool XORRectangle::initialised() const
{
    return !!cr;
}

void XORRectangle::lazy_init()
{
    if (!initialised()) {
        cr = gdk_cairo_create(gtk_widget_get_window(m_widget));
    }
}

void XORRectangle::draw() const
{
    const int x = float_to_integer(m_rectangle.x);
    const int y = float_to_integer(m_rectangle.y);
    const int w = float_to_integer(m_rectangle.w);
    const int h = float_to_integer(m_rectangle.h);
    GtkAllocation allocation;
    gtk_widget_get_allocation(m_widget, &allocation);
    cairo_rectangle(cr, x, -(h) - (y - allocation.height), w, h);
    cairo_set_source_rgb(cr, 1, 1, 1);
    cairo_set_operator(cr, CAIRO_OPERATOR_DIFFERENCE);
    cairo_stroke(cr);
}

XORRectangle::XORRectangle(ui::GLArea widget) : m_widget(widget), cr(0)
{
}

XORRectangle::~XORRectangle()
{
    if (initialised()) {
        cairo_destroy(cr);
    }
}

void XORRectangle::set(rectangle_t rectangle)
{
    if (gtk_widget_get_realized(m_widget)) {
        lazy_init();
        draw();
        m_rectangle = rectangle;
        draw();
    }
}