cleaner code, return and continue instead of put inside a large if

1 files changed, 86 insertions, 87 deletions

diff --git a/remote_plot.c b/remote_plot.c
index 512e40c..9fe3b1d 100644
--- a/remote_plot.c
+++ b/remote_plot.c
@@ -474,108 +474,107 @@ static void draw_function (GtkDrawingArea *area,
 		gpointer        user_data)
 {
 	DATA *data=user_data;
-	if(!ListIsEmpty(&(data->cans)))
-	{
-		//printf("draw begin\n");
-		//PLFLT xmin=data->cans.head->item.t;
-		//PLFLT xmax=data->cans.end->item.t;
-		PLFLT xmin,xmax;
-		PLFLT ymin, ymax;
-		int plot_counts=0;
-		gboolean active_checkbutton[VOLTLEN+TEMPLEN];
-
-		if(gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(data->live_toggle)))
-			xmax=data->cans.end->item.t;
-		else
-			xmax=data->to_time;
+	if(ListIsEmpty(&data->cans))
+		return;
+
+	//printf("draw begin\n");
+	//PLFLT xmin=data->cans.head->item.t;
+	//PLFLT xmax=data->cans.end->item.t;
+	PLFLT xmin,xmax;
+	PLFLT ymin, ymax;
+	int plot_counts=0;
+	gboolean active_checkbutton[VOLTLEN+TEMPLEN];
+
+	if(gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(data->live_toggle)))
+		xmax=data->cans.end->item.t;
+	else
+		xmax=data->to_time;
 
-		if(data->from_time_entered)
-			xmin=data->from_time;
-		else
-			xmin=data->cans.head->item.t;
+	if(data->from_time_entered)
+		xmin=data->from_time;
+	else
+		xmin=data->cans.head->item.t;
 
-		for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
-			if((active_checkbutton[i]=gtk_check_button_get_active(GTK_CHECK_BUTTON(data->checkbutton[i]))))
-				plot_counts++;
+	for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
+		if((active_checkbutton[i]=gtk_check_button_get_active(GTK_CHECK_BUTTON(data->checkbutton[i]))))
+			plot_counts++;
 
-		plsdev( "extcairo" );
+	plsdev( "extcairo" );
 
+	{
+		char str[12];
+		sprintf(str,"%dx%d",
+				gtk_widget_get_width(data->area),
+				gtk_widget_get_height(data->area));
+		plsetopt("geometry", str);
+	}
+
+	// change to white background and black foreground, and gray color palette
+	// http://plplot.sourceforge.net/docbook-manual/plplot-html-5.15.0/color.html
+	// seems should be put before plinit; or need pladv(), plvpor(), plwind() for a new picture?
+	// more see example 16
+	// http://plplot.sourceforge.net/examples.php?demo=16
+	// /usr/share/plplot5.15.0/examples/c/x16c.c
+	plspal0("cmap0_black_on_white.pal");
+	plspal1("cmap1_gray.pal", 1);
+
+	// Initialize plplot
+	if(plot_counts>3)
+		plstar(3,(plot_counts+2)/3);
+	else
+		plstar(1,plot_counts);
+	pl_cmd( PLESC_DEVINIT, cr );
+
+	// 10 char unix time: 1745925459
+	// set numbers of digits to display x axis labels
+	plsxax(10,0);
+
+	for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
+	{
+		if(!active_checkbutton[i])
+			continue;
+		if(i<VOLTLEN)
 		{
-			char str[12];
-			sprintf(str,"%dx%d",
-					gtk_widget_get_width(data->area),
-					gtk_widget_get_height(data->area));
-			plsetopt("geometry", str);
+			// according to .dbc file
+			ymin=0;
+			ymax=6.;
 		}
-
-		// change to white background and black foreground, and gray color palette
-		// http://plplot.sourceforge.net/docbook-manual/plplot-html-5.15.0/color.html
-		// seems should be put before plinit; or need pladv(), plvpor(), plwind() for a new picture?
-		// more see example 16
-		// http://plplot.sourceforge.net/examples.php?demo=16
-		// /usr/share/plplot5.15.0/examples/c/x16c.c
-		plspal0("cmap0_black_on_white.pal");
-		plspal1("cmap1_gray.pal", 1);
-
-		// Initialize plplot
-		if(plot_counts>3)
-			plstar(3,(plot_counts+2)/3);
 		else
-			plstar(1,plot_counts);
-		pl_cmd( PLESC_DEVINIT, cr );
-
-		// 10 char unix time: 1745925459
-		// set numbers of digits to display x axis labels
-		plsxax(10,0);
+		{
+			// according to .dbc file
+			ymin=-50;
+			ymax=100;
+		}
 
-		for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
+		// Create a labelled box to hold the plot.
+		plenv(xmin, xmax, ymin, ymax, 0, 0);
+		if(i<VOLTLEN)
+			pllab("Time (s)","Voltage (V)",checkbutton_names[i]);
+		else
+			pllab("Time (s)","Temperature (C)",checkbutton_names[i]);
+		// Plot the data that was prepared above.
+		// plstring or plptex for scatter
+		// #(NNN) is Hershey font code, more see example 5, 6, 21
+		// #(727) is centred X symbol; other maybe useful codes: #(728)
+		// hershey font code see http://plplot.sourceforge.net/examples.php?demo=07 ?
 		{
-			if(active_checkbutton[i])
+			Node * pnode = data->cans.head;
+			while(pnode!=NULL && ((pnode->item.t <= xmax) || gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(data->live_toggle))) )
 			{
-				if(i<VOLTLEN)
+				if(pnode->item.t >= xmin)
 				{
-					// according to .dbc file
-					ymin=0;
-					ymax=6.;
-				}
-				else
-				{
-					// according to .dbc file
-					ymin=-50;
-					ymax=100;
-				}
-
-				// Create a labelled box to hold the plot.
-				plenv(xmin, xmax, ymin, ymax, 0, 0);
-				if(i<VOLTLEN)
-					pllab("Time (s)","Voltage (V)",checkbutton_names[i]);
-				else
-					pllab("Time (s)","Temperature (C)",checkbutton_names[i]);
-				// Plot the data that was prepared above.
-				// plstring or plptex for scatter
-				// #(NNN) is Hershey font code, more see example 5, 6, 21
-				// #(727) is centred X symbol; other maybe useful codes: #(728)
-				// hershey font code see http://plplot.sourceforge.net/examples.php?demo=07 ?
-				{
-					Node * pnode = data->cans.head;
-					while(pnode!=NULL && ((pnode->item.t <= xmax) || gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(data->live_toggle))) )
-					{
-						if(pnode->item.t >= xmin)
-						{
-							if(i<VOLTLEN)
-								plptex(pnode->item.t,pnode->item.volt[i],1.,0.,0.5,"#(727)");
-							else
-								plptex(pnode->item.t,pnode->item.temp[i-VOLTLEN],1.,0.,0.5,"#(727)");
-						}
-						pnode=pnode->next;
-					}
+					if(i<VOLTLEN)
+						plptex(pnode->item.t,pnode->item.volt[i],1.,0.,0.5,"#(727)");
+					else
+						plptex(pnode->item.t,pnode->item.temp[i-VOLTLEN],1.,0.,0.5,"#(727)");
 				}
+				pnode=pnode->next;
 			}
 		}
-
-		// Close PLplot library
-		plend();
 	}
+
+	// Close PLplot library
+	plend();
 }
 
 static void print_data (GtkWidget *widget, gpointer user_data)