Add functionality to draw lines via command

* action: add a --line command line option for drawing lines

* targets: add GA_LINE and GA_LINEDATA targets to allow cli to send
parameters to the main app

* chore: remove debug logs

* chore: formatting fixes

* callbacks: free line_ctx, might prevent potential memory leak

* README: add docs for --line command

* callbacks: fix memory leak

* main: indentation fixes

* cmdline: failsafe checks

* cmdline: fix minor failsafe check bug

* README: add line example

* README: indentation error

* README: add quotes around color argument

README.md

@@ -96,6 +96,9 @@ Usage:
         will undo the last drawing stroke (or "-z")
     gromit-mpx --redo
         will redo the last undone drawing stroke (or "-y")
+    gromit-mpx --line <startX> <startY> <endX> <endY> <color> <thickness>
+        will draw a straight line with characteristics specified by the arguments (or "-l")
+        eg: gromit-mpx -l 200 200 400 400 '#C4A7E7' 6	
 
 If activated Gromit-MPX prevents you from using other programs with the
 mouse. You can press the button and paint on the screen. Key presses

src/callbacks.c

@@ -205,7 +205,8 @@ void on_clientapp_selection_get (GtkWidget          *widget,
   if(data->debug)
     g_printerr("DEBUG: clientapp received request.\n");  
 
-  if (gtk_selection_data_get_target(selection_data) == GA_TOGGLEDATA)
+
+  if (gtk_selection_data_get_target(selection_data) == GA_TOGGLEDATA || gtk_selection_data_get_target(selection_data) == GA_LINEDATA)
     {
       ans = data->clientdata;
     }
@@ -435,6 +436,13 @@ void on_mainapp_selection_get (GtkWidget          *widget,
                              GA_TOGGLEDATA, time);
       gtk_main(); /* Wait for the response */
     }
+  else if(action == GA_LINE)
+    {
+      /* ask back client for device id */
+      gtk_selection_convert (data->win, GA_DATA,
+                             GA_LINEDATA, time);
+      gtk_main(); /* Wait for the response */
+    }
   else if (action == GA_VISIBILITY)
     toggle_visibility (data);
   else if (action == GA_CLEAR)
@@ -502,6 +510,59 @@ void on_mainapp_selection_received (GtkWidget *widget,
 		g_printerr("ERROR: No device at index %ld.\n", (long)dev_nr);
 	    }
         }
+      else if (gtk_selection_data_get_target(selection_data) == GA_LINEDATA) 
+	{
+
+	  gchar** line_args = g_strsplit((gchar*)gtk_selection_data_get_data(selection_data), " ", 6);
+	  int startX = atoi(line_args[0]);
+	  int startY = atoi(line_args[1]);
+	  int endX = atoi(line_args[2]);
+	  int endY = atoi(line_args[3]);
+	  gchar* hex_code = line_args[4];
+	  int thickness = atoi(line_args[5]);
+
+          if(data->debug) 
+	    {
+	      g_printerr("DEBUG: mainapp got line data back from client:\n");
+	      g_printerr("startX startY endX endY: %d %d %d %d\n", startX, startY, endX, endY);
+	      g_printerr("color: %s\n", hex_code);
+	      g_printerr("thickness: %d\n", thickness);
+	    }
+
+	  GdkRGBA* color = g_malloc (sizeof (GdkRGBA));
+	  GdkRGBA *fg_color=data->red;
+	  if (gdk_rgba_parse (color, hex_code))
+	    {
+	      fg_color = color;
+	    }
+	  else
+	    {
+	      g_printerr ("Unable to parse color. "
+	      "Keeping default.\n");
+	    }
+	  GromitPaintContext* line_ctx = paint_context_new(data, GROMIT_PEN, fg_color, thickness, 0, thickness, thickness);
+
+	  GdkRectangle rect;
+	  rect.x = MIN (startX,endX) - thickness / 2;
+	  rect.y = MIN (startY,endY) - thickness / 2;
+	  rect.width = ABS (startX-endX) + thickness;
+	  rect.height = ABS (startY-endY) + thickness;
+
+	  if(data->debug)
+	    g_printerr("DEBUG: draw line from %d %d to %d %d\n", startX, startY, endX, endY);
+
+	  cairo_set_line_width(line_ctx->paint_ctx, thickness);
+	  cairo_move_to(line_ctx->paint_ctx, startX, startY);
+	  cairo_line_to(line_ctx->paint_ctx, endX, endY);
+	  cairo_stroke(line_ctx->paint_ctx);
+
+	  data->modified = 1;
+	  gdk_window_invalidate_rect(gtk_widget_get_window(data->win), &rect, 0); 
+	  data->painted = 1;
+
+	  g_free(line_ctx);
+	  g_free (color);
+	}
     }
 
   gtk_main_quit ();

src/main.c

@@ -653,6 +653,7 @@ void setup_main_app (GromitData *data, int argc, char ** argv)
   gtk_selection_add_target (data->win, GA_CONTROL, GA_RELOAD, 7);
   gtk_selection_add_target (data->win, GA_CONTROL, GA_UNDO, 8);
   gtk_selection_add_target (data->win, GA_CONTROL, GA_REDO, 9);
+  gtk_selection_add_target (data->win, GA_CONTROL, GA_LINE, 10);
 
 
 
@@ -982,6 +983,40 @@ int main_client (int argc, char **argv, GromitData *data)
            else
              data->clientdata = "-1"; /* default to grab all */
          }
+       else if (strcmp (arg, "-l") == 0 ||
+           strcmp (arg, "--line") == 0)
+         {
+           if (argc - (i+1) == 6) /* this command must have exactly 6 params */
+             {
+
+                // check if provided values are valid coords on the screen
+               if (atoi(argv[i+1]) < 0 || atoi(argv[i+1]) > (int)data->width || 
+                   atoi(argv[i+2]) < 0 || atoi(argv[i+2]) > (int)data->height ||
+                   atoi(argv[i+3]) < 0 || atoi(argv[i+3]) > (int)data->width ||
+                   atoi(argv[i+4]) < 0 || atoi(argv[i+4]) > (int)data->height)
+                    {
+                      g_printerr ("Invalid coordinates\n");
+                      wrong_arg = TRUE;
+                    }
+               else if (atoi(argv[i+6]) < 1)
+                    {
+                      g_printerr ("Thickness must be atleast 1\n");
+                      wrong_arg = TRUE;
+                    }
+               else 
+                    {
+                      data->clientdata = g_strjoin(" ", argv[i+1], argv[i+2], argv[i+3], argv[i+4], argv[i+5], argv[i+6], NULL);
+                    }
+
+               action = GA_LINE;
+               i += 6;
+             }
+           else 
+             {
+               g_printerr ("-l requires 6 parameters: startX, startY, endX, endY, color, thickness\n");
+               wrong_arg = TRUE;
+             }
+         }
        else if (strcmp (arg, "-v") == 0 ||
                 strcmp (arg, "--visibility") == 0)
          {
@@ -1093,6 +1128,7 @@ int main (int argc, char **argv)
 
   gtk_selection_owner_set (data->win, GA_DATA, GDK_CURRENT_TIME);
   gtk_selection_add_target (data->win, GA_DATA, GA_TOGGLEDATA, 1007);
+  gtk_selection_add_target (data->win, GA_DATA, GA_LINEDATA, 1008);
 
 
 

src/main.h

@@ -48,6 +48,7 @@
 #define GA_ACTIVATE   gdk_atom_intern ("Gromit/activate", FALSE)
 #define GA_DEACTIVATE gdk_atom_intern ("Gromit/deactivate", FALSE)
 #define GA_TOGGLE     gdk_atom_intern ("Gromit/toggle", FALSE)
+#define GA_LINE       gdk_atom_intern ("Gromit/line", FALSE)
 #define GA_VISIBILITY gdk_atom_intern ("Gromit/visibility", FALSE)
 #define GA_CLEAR      gdk_atom_intern ("Gromit/clear", FALSE)
 #define GA_RELOAD     gdk_atom_intern ("Gromit/reload", FALSE)
@@ -56,6 +57,7 @@
 
 #define GA_DATA       gdk_atom_intern ("Gromit/data", FALSE)
 #define GA_TOGGLEDATA gdk_atom_intern ("Gromit/toggledata", FALSE)
+#define GA_LINEDATA   gdk_atom_intern ("Gromit/linedata", FALSE)
 
 #define GROMIT_MAX_UNDO 4