[goocanvas/wip/albfan/rotate-skew-demo: 3/3] Rotate Skew demo

[Alberto Fanjul <albfan src gnome org>]

commit f2a55dcb3df019bb509e0629fe73ff4f864c952f
Author: Alberto Fanjul <albertofanjul gmail com>
Date:   Mon Mar 11 01:55:44 2019 +0100

    Rotate Skew demo
    
    Added example to move, resize, rotate and skew

 .gitignore                 |   1 +
 demo/Makefile.am           |   7 +-
 demo/mv-rotate-skew-demo.c | 274 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 281 insertions(+), 1 deletion(-)
---
diff --git a/.gitignore b/.gitignore
index 618498f..ca651a9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,6 +31,7 @@ Makefile.in
 /demo/mv-scalability-demo
 /demo/mv-simple-demo
 /demo/mv-table-demo
+/demo/mv-rotate-skew-demo
 /demo/scalability-demo
 /demo/simple-demo
 /demo/table-demo
diff --git a/demo/Makefile.am b/demo/Makefile.am
index 5a2466c..55edc04 100644
--- a/demo/Makefile.am
+++ b/demo/Makefile.am
@@ -11,7 +11,7 @@ DEMO_LIBS = $(top_builddir)/src/libgoocanvas-3.0.la @PACKAGE_LIBS@ $(INTLLIBS) -
 #      -DGDK_DISABLE_DEPRECATED -DGDK_PIXBUF_DISABLE_DEPRECATED \
 #      -DGTK_DISABLE_DEPRECATED
 
-noinst_PROGRAMS = demo table-demo generic-position-demo simple-demo scalability-demo units-demo widgets-demo 
mv-demo mv-table-demo mv-generic-position-demo mv-simple-demo mv-scalability-demo
+noinst_PROGRAMS = demo table-demo generic-position-demo simple-demo scalability-demo units-demo widgets-demo 
mv-demo mv-table-demo mv-generic-position-demo mv-simple-demo mv-scalability-demo mv-rotate-skew-demo
 
 demo_SOURCES = \
        demo.c demo-fifteen.c demo-scalability.c demo-grabs.c \
@@ -75,6 +75,11 @@ generic_position_demo_SOURCES = \
 
 generic_position_demo_LDADD = $(DEMO_LIBS)
 
+mv_rotate_skew_demo_SOURCES = \
+       mv-rotate-skew-demo.c
+
+mv_rotate_skew_demo_LDADD = $(DEMO_LIBS)
+
 mv_generic_position_demo_SOURCES = \
        mv-generic-position-demo.c
 
diff --git a/demo/mv-rotate-skew-demo.c b/demo/mv-rotate-skew-demo.c
new file mode 100644
index 0000000..fa01f9c
--- /dev/null
+++ b/demo/mv-rotate-skew-demo.c
@@ -0,0 +1,274 @@
+#include <stdlib.h>
+#include <math.h>
+#include <goocanvas.h>
+
+typedef enum {
+  MODE_MOVE,
+  MODE_RESIZE,
+  MODE_ROTATE,
+  MODE_SKETCH
+} Mode;
+
+Mode             drag_mode;
+GooCanvasItem   *drag_item = NULL;
+gdouble          drag_x = 0.0;
+gdouble          drag_y = 0.0;
+
+gdouble          item_x = 0.0;
+gdouble          item_y = 0.0;
+gdouble          item_width = 0.0;
+gdouble          item_height = 0.0;
+
+gdouble          canvas_event_x = 0.0;
+gdouble          canvas_event_y = 0.0;
+
+static gboolean
+on_button_press_event_cb (GooCanvasItem *item,
+                          GooCanvasItem *target_item,
+                          GdkEventButton *event,
+                          gpointer user_data)
+{
+  GooCanvasItemModel *model = goo_canvas_item_get_model (item);
+  if (event->state & GDK_CONTROL_MASK || event->state & GDK_SHIFT_MASK)
+  {
+    if (event->button == 1 || event->button == 3)
+    {
+      if (event->state & GDK_CONTROL_MASK)
+      {
+        if (event->button == 1)
+        {
+          drag_mode = MODE_MOVE;
+        }
+        else
+        {
+          drag_mode = MODE_RESIZE;
+        }
+      }
+      else
+      {
+        if (event->button == 1)
+        {
+          drag_mode = MODE_ROTATE;
+        }
+        else
+        {
+          drag_mode = MODE_SKETCH;
+        }
+      }
+
+      drag_item = item;
+      drag_x = event->x;
+      drag_y = event->y;
+      canvas_event_x = event->x;
+      canvas_event_y = event->y;
+      goo_canvas_convert_from_item_space(GOO_CANVAS(user_data), item, &canvas_event_x, &canvas_event_y);
+
+      g_object_get (G_OBJECT (model),
+                    "x", &item_x,
+                    "y", &item_y,
+                    "width", &item_width,
+                    "height", &item_height,
+                    NULL);
+
+      goo_canvas_pointer_grab (GOO_CANVAS (user_data), item, GDK_POINTER_MOTION_MASK | 
GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_RELEASE_MASK, NULL, event->time);
+      return TRUE;
+    }
+  }
+
+  return FALSE;
+}
+
+static gboolean
+on_button_release_event_cb (GooCanvasItem  *item,
+                            GooCanvasItem  *target_item,
+                            GdkEventButton *event,
+                            gpointer user_data)
+{
+  if (drag_item == item && drag_item != NULL)
+  {
+    goo_canvas_pointer_ungrab (GOO_CANVAS (user_data), drag_item, event->time);
+    drag_item = NULL;
+    g_object_get (G_OBJECT (item),
+                  "x", &item_x,
+                  "y", &item_y,
+                  "width", &item_width,
+                  "height", &item_height,
+                  NULL);
+    return TRUE;
+  }
+
+  return FALSE;
+}
+
+static gboolean
+on_motion_notify_event_cb (GooCanvasItem  *item,
+                           GooCanvasItem  *target_item,
+                           GdkEventMotion *event,
+                           gpointer user_data)
+{
+  GooCanvasItemModel *model = goo_canvas_item_get_model (item);
+
+  GooCanvas *canvas = GOO_CANVAS(user_data);
+
+  gboolean ret = FALSE;
+
+  gdouble canvas_temp_event_x = event->x, canvas_temp_event_y = event->y;
+  goo_canvas_convert_from_item_space(canvas, item, &canvas_temp_event_x, &canvas_temp_event_y);
+
+  if (drag_item == item && drag_item != NULL)
+  {
+    gdouble rel_x = event->x - drag_x;
+    gdouble rel_y = event->y - drag_y;
+
+    if (drag_mode == MODE_MOVE)
+    {
+      goo_canvas_item_translate (item, rel_x, rel_y);
+    }
+    else if (drag_mode == MODE_RESIZE)
+    {
+      gdouble new_width = MAX (item_width + rel_x, 5.0);
+      gdouble new_height = MAX (item_height + rel_y, 5.0);
+
+      g_object_set (G_OBJECT (model), "width", new_width, "height", new_height, NULL);
+    }
+    else
+    {
+      double center_x = item_x + item_width / 2.0f;
+      double center_y = item_y + item_height / 2.0f;
+
+      gdouble canvas_center_x = center_x, canvas_center_y = center_y;
+      goo_canvas_convert_from_item_space (canvas, item, &canvas_center_x, &canvas_center_y);
+
+      double start_radians = atan2 (canvas_center_y - canvas_temp_event_y, canvas_temp_event_x - 
canvas_center_x );
+      double radians = atan2 (canvas_center_y - canvas_event_y, canvas_event_x - canvas_center_x );
+      radians = radians - start_radians;
+      double rotation = radians * (180 / M_PI);
+
+      if (drag_mode == MODE_ROTATE)
+      {
+        goo_canvas_item_model_rotate(model, rotation, center_x, center_y);
+      }
+      else
+      {
+        if (canvas_event_x - canvas_temp_event_x != 0)
+        {
+          goo_canvas_item_model_skew_x(model, rotation, center_x, center_y);
+        }
+        if (canvas_event_y - canvas_temp_event_y != 0)
+        {
+          goo_canvas_item_model_skew_y(model, rotation, center_x, center_y);
+        }
+      }
+    }
+
+    ret = TRUE;
+  }
+
+  canvas_event_x = canvas_temp_event_x;
+  canvas_event_y = canvas_temp_event_y;
+
+  return ret;
+}
+
+
+static void
+on_item_created (GooCanvas          *canvas,
+                GooCanvasItem      *item,
+                GooCanvasItemModel *model,
+                gpointer            data)
+{
+  if (g_object_get_data (G_OBJECT (model), "setup-dnd-signals"))
+    {
+      g_signal_connect (G_OBJECT (item), "button-press-event", G_CALLBACK (on_button_press_event_cb), 
canvas);
+      g_signal_connect (G_OBJECT (item), "button-release-event", G_CALLBACK (on_button_release_event_cb), 
canvas);
+      g_signal_connect (G_OBJECT (item), "grab-broken-event", G_CALLBACK (on_button_release_event_cb), 
canvas);
+      g_signal_connect (G_OBJECT (item), "motion-notify-event", G_CALLBACK (on_motion_notify_event_cb), 
canvas);
+    }
+}
+
+
+static GooCanvasItemModel*
+create_model (GdkPixbuf *pixbuf)
+{
+  GooCanvasItemModel *root;
+  GooCanvasItemModel *item;
+  GooCanvasItemModel* child;
+
+  root = goo_canvas_group_model_new (NULL, NULL);
+
+  child = goo_canvas_rect_model_new (root, 0.0, 0.0, 100, 100, "fill-color", "blue", NULL);
+  g_object_set_data (G_OBJECT (child), "setup-dnd-signals", "TRUE");
+
+  child = goo_canvas_ellipse_model_new (root, 150, 0, 50, 50, "fill-color", "red", NULL);
+  g_object_set_data (G_OBJECT (child), "setup-dnd-signals", "TRUE");
+
+  return root;
+}
+
+
+static GtkWidget*
+create_window (GooCanvasItemModel *model)
+{
+  GtkWidget *window, *vbox, *label, *scrolled_win, *canvas;
+
+  /* Create the window and widgets. */
+  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+  gtk_window_set_default_size (GTK_WINDOW (window), 640, 600);
+  gtk_widget_show (window);
+  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
+
+  vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 4);
+  gtk_container_set_border_width (GTK_CONTAINER (vbox), 4);
+  gtk_widget_show (vbox);
+  gtk_container_add (GTK_CONTAINER (window), vbox);
+
+  label = gtk_label_new ("Use Ctrl+Left Click to move items or Ctrl+Right Click to resize items");
+  g_object_set (label, "halign", GTK_ALIGN_START, NULL);
+  gtk_box_pack_start (GTK_BOX (vbox), label, FALSE, FALSE, 0);
+  gtk_widget_show (label);
+
+  /* Create top canvas. */
+  scrolled_win = gtk_scrolled_window_new (NULL, NULL);
+  gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (scrolled_win),
+                                       GTK_SHADOW_IN);
+  gtk_widget_show (scrolled_win);
+  gtk_box_pack_start (GTK_BOX (vbox), scrolled_win, TRUE, TRUE, 0);
+
+  canvas = goo_canvas_new ();
+  g_object_set (G_OBJECT (canvas), "integer-layout", TRUE, NULL);
+  goo_canvas_set_bounds (GOO_CANVAS (canvas), 0, 0, 1000, 1000);
+  gtk_widget_show (canvas);
+  gtk_container_add (GTK_CONTAINER (scrolled_win), canvas);
+
+  g_signal_connect (canvas, "item_created", G_CALLBACK (on_item_created), NULL);
+
+  goo_canvas_set_root_item_model (GOO_CANVAS (canvas), model);
+
+  return window;
+}
+
+
+int
+main (int argc, char *argv[])
+{
+  GooCanvasItemModel *model;
+  GdkPixbuf *pixbuf;
+
+  gtk_init (&argc, &argv);
+
+  pixbuf = gtk_icon_theme_load_icon (gtk_icon_theme_get_default (), "dialog-warning", 48, 0, NULL);
+
+  model = create_model (pixbuf);
+
+  /* Create 2 windows to show off multiple views. */
+  create_window (model);
+#if 0 //set to 1 if you want to see a second view
+  create_window (model);
+#endif
+
+  g_object_unref (model);
+
+  gtk_main ();
+
+  return 0;
+}