// --------------------------------------------------------------------
// ipe::Canvas for GTK
// --------------------------------------------------------------------
/*

    This file is part of the extensible drawing editor Ipe.
    Copyright (c) 1993-2020 Otfried Cheong

    Ipe is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    As a special exception, you have permission to link Ipe with the
    CGAL library and distribute executables, as long as you follow the
    requirements of the Gnu General Public License in regard to all of
    the software in the executable aside from CGAL.

    Ipe is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
    License for more details.

    You should have received a copy of the GNU General Public License
    along with Ipe; if not, you can find it at
    "http://www.gnu.org/copyleft/gpl.html", or write to the Free
    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include "ipecanvas_gtk.h"
#include "ipecairopainter.h"
#include "ipetool.h"

#include <cairo.h>

using namespace ipe;

// --------------------------------------------------------------------

void Canvas::invalidate()
{
  GdkRectangle r;
  r.x = r.y = 0;
#if GTK_MAJOR_VERSION >= 3
  r.width = gtk_widget_get_allocated_width(iWindow);
  r.height = gtk_widget_get_allocated_height(iWindow);
#else
  r.width = iWindow->allocation.width;
  r.height = iWindow->allocation.height;
#endif
  gdk_window_invalidate_rect(gtk_widget_get_window(iWindow), &r, FALSE);
}

void Canvas::invalidate(int x, int y, int w, int h)
{
  GdkRectangle r;
  r.x = x; r.y = y;
  r.width = w; r.height = h;
  gdk_window_invalidate_rect(gtk_widget_get_window(iWindow), &r, FALSE);
}

// --------------------------------------------------------------------

void Canvas::buttonHandler(GdkEventButton *ev)
{
  // ipeDebug("Canvas::button %d %d %g %g", ev->button, ev->type, ev->x, ev->y);
  iGlobalPos = Vector(ev->x_root, ev->y_root);
  computeFifi(ev->x, ev->y);
  // TODO: int mod = getModifiers() | iAdditionalModifiers;
  int mod = iAdditionalModifiers;
  bool down = (ev->type == GDK_BUTTON_PRESS);
  if (iTool)
    iTool->mouseButton(ev->button | mod, down);
  else if (down && iObserver)
    iObserver->canvasObserverMouseAction(ev->button | mod);
}

void Canvas::motionHandler(GdkEventMotion *event)
{
  // ipeDebug("Canvas::mouseMove %g %g", event->x, event->y);
  computeFifi(event->x, event->y);
  if (iTool)
    iTool->mouseMove();
  if (iObserver)
    iObserver->canvasObserverPositionChanged();
}

void Canvas::scrollHandler(GdkEventScroll *event)
{
  int zDelta = (event->direction == GDK_SCROLL_UP) ? 120 : -120;
  // ipeDebug("Canvas::wheel %d", zDelta);
  if (iObserver)
    iObserver->canvasObserverWheelMoved(zDelta);
}

#if GTK_MAJOR_VERSION >= 3
void Canvas::exposeHandler(cairo_t *cr)
{
  iWidth = gtk_widget_get_allocated_width(iWindow);
  iHeight = gtk_widget_get_allocated_height(iWindow);
#else
void Canvas::exposeHandler(GdkEventExpose *event)
 {
  iWidth = iWindow->allocation.width;
  iHeight = iWindow->allocation.height;
#endif

  refreshSurface();

#if GTK_MAJOR_VERSION < 3
  cairo_t *cr = gdk_cairo_create(iWindow->window);
  cairo_rectangle(cr, event->area.x, event->area.y,
		  event->area.width, event->area.height);
  cairo_clip(cr);
#endif

  cairo_set_source_surface(cr, iSurface, 0.0, 0.0);
  cairo_paint(cr);

  if (iFifiVisible)
    drawFifi(cr);

  if (iPage) {
    CairoPainter cp(iCascade, iFonts, cr, iZoom, false);
    cp.transform(canvasTfm());
    cp.pushMatrix();
    drawTool(cp);
    cp.popMatrix();
  }
#if GTK_MAJOR_VERSION < 3
  cairo_destroy(cr);
#endif
}

// --------------------------------------------------------------------

gboolean Canvas::button_cb(GtkWidget *widget, GdkEvent *event, Canvas *canvas)
{
  canvas->buttonHandler((GdkEventButton *) event);
  return TRUE;
}

#if GTK_MAJOR_VERSION < 3
gboolean Canvas::expose_cb(GtkWidget *widget, GdkEvent *event, Canvas *canvas)
{
  canvas->exposeHandler((GdkEventExpose *) event);
  return TRUE;
}
#else
gboolean Canvas::expose_cb(GtkWidget *widget, cairo_t *cr, Canvas *canvas)
{
  canvas->exposeHandler(cr);
  return TRUE;
}
#endif

gboolean Canvas::motion_cb(GtkWidget *widget, GdkEvent *event, Canvas *canvas)
{
  canvas->motionHandler((GdkEventMotion *) event);
  return TRUE;
}

gboolean Canvas::scroll_cb(GtkWidget *widget, GdkEvent *event, Canvas *canvas)
{
  canvas->scrollHandler((GdkEventScroll *) event);
  return TRUE;
}

void Canvas::setCursor(TCursor cursor, double w, Color *color)
{
  // TODO
}

// --------------------------------------------------------------------

Canvas::Canvas(GtkWidget *parent)
{
  iWindow = gtk_drawing_area_new();
  gtk_widget_add_events(iWindow,
			GDK_BUTTON_PRESS_MASK|
			GDK_BUTTON_RELEASE_MASK|
			GDK_POINTER_MOTION_MASK);
  gtk_widget_set_size_request(iWindow, 600, 400);
  gtk_widget_set_can_focus(iWindow, TRUE);
  g_signal_connect(G_OBJECT(iWindow), "button-release-event",
		   G_CALLBACK(button_cb), this);
  g_signal_connect(G_OBJECT(iWindow), "button-press-event",
		   G_CALLBACK(button_cb), this);
#if GTK_MAJOR_VERSION < 3
  g_signal_connect(G_OBJECT(iWindow), "expose-event",
		   G_CALLBACK(expose_cb), this);
#else
  g_signal_connect(G_OBJECT(iWindow), "draw",
		   G_CALLBACK(expose_cb), this);
#endif
  g_signal_connect(G_OBJECT(iWindow), "motion-notify-event",
		   G_CALLBACK(motion_cb), this);
  g_signal_connect(G_OBJECT(iWindow), "scroll-event",
		   G_CALLBACK(scroll_cb), this);
}

Canvas::~Canvas()
{
  // do I need to delete the GTK Window?  It is owned by its parent.
}

// --------------------------------------------------------------------
