X11: Add a button for writing an SVG file to the plot window.

Update button texts.
Add a function hardcopySVG to write the SVG file, called by
clicking the SVG button.

src/frontend/plotting/x11.c

@@ -65,7 +65,7 @@ Author: 1988 Jeffrey M. Hsu
 typedef struct x11info {
     Window window;
     int isopen;
-    Widget shell, form, view, buttonbox, buttons[2];
+    Widget shell, form, view, buttonbox, buttons[3];
     XFontStruct *font;
     GC gc; /* graphics context for graphs */
     GC gridgc; /* graphics context for grid, linewidth may differ */
@@ -131,6 +131,7 @@ static void resize(Widget w, XtPointer client_data, XEvent *ev, Boolean *continu
 
 //XtCallbackProc
 static void hardcopy(Widget w, XtPointer client_data, XtPointer call_data);
+static void hardcopySVG(Widget w, XtPointer client_data, XtPointer call_data);
 static void killwin(Widget w, XtPointer client_data, XtPointer call_data);
 
 int X11_GetLenStr(GRAPH* gr, char* instring);
@@ -505,18 +506,23 @@ X11_NewViewport(GRAPH *graph)
         ("buttonbox", boxWidgetClass, DEVDEP(graph).form, bboxargs, XtNumber(bboxargs));
 
     /* set up buttons */
-    XtSetArg(buttonargs[0], XtNlabel, "quit");
+    XtSetArg(buttonargs[0], XtNlabel, "Quit");
     XtSetArg(bboxargs[1], XtNfromVert, NULL);
     DEVDEP(graph).buttons[0] = XtCreateManagedWidget
         ("quit", commandWidgetClass, DEVDEP(graph).buttonbox, buttonargs, 1);
     XtAddCallback(DEVDEP(graph).buttons[0], XtNcallback, killwin, graph);
 
-    XtSetArg(buttonargs[0], XtNlabel, "hardcopy");
+    XtSetArg(buttonargs[0], XtNlabel, "PostScript");
     XtSetArg(bboxargs[1], XtNfromVert, DEVDEP(graph).buttons[0]);
     DEVDEP(graph).buttons[1] = XtCreateManagedWidget
         ("hardcopy", commandWidgetClass, DEVDEP(graph).buttonbox, buttonargs, 1);
     XtAddCallback(DEVDEP(graph).buttons[1], XtNcallback, hardcopy, graph);
 
+    XtSetArg(buttonargs[0], XtNlabel, "SVG");
+    DEVDEP(graph).buttons[2] = XtCreateManagedWidget(
+        "SVG", commandWidgetClass, DEVDEP(graph).buttonbox, buttonargs, 1);
+    XtAddCallback(DEVDEP(graph).buttons[2], XtNcallback, hardcopySVG, graph);
+
     /* set up fonts */
     if (!cp_getvar("xfont", CP_STRING, fontname, sizeof(fontname)))
         (void) strcpy(fontname, DEF_FONT);
@@ -726,7 +732,7 @@ X11_Text(const char *text, int x, int y, int angle)
 #ifndef HAVE_LIBXFT
     if (DEVDEP(currentgraph).isopen) {
         if (angle != 0) {
-            fprintf(stderr, " Xft: angles other than 0 are not supported\n");
+            fprintf(stderr, " No Xft: angles other than 0 are not supported\n");
         }
         XDrawString(display, DEVDEP(currentgraph).window,
                     DEVDEP(currentgraph).gc, x,
@@ -1066,6 +1072,7 @@ zoomin(GRAPH *graph)
     }
 
     strncpy(buf2, graph->plotname, sizeof(buf2) - 1);
+    buf2[sizeof buf2 - 1] = '\0';
     if ((t = strchr(buf2, ':')) != NULL)
         *t = '\0';
 
@@ -1103,6 +1110,11 @@ hardcopy(Widget w, XtPointer client_data, XtPointer call_data)
     NG_IGNORE(call_data);
     NG_IGNORE(w);
 
+    int i = 1;
+    cp_vset("hcopydevtype", CP_STRING, "postscript");
+    /* If not set, the color will be b&w, i = 1 is white background */
+    cp_vset("hcopypscolor", CP_NUM, &i);
+
     /* com_hardcopy() -> gr_resize() -> setcolor() during postscript
        printing will act on currentgraph with a DEVDEP inherited from PSdevdep.
        But currentgraph had not changed its devdep, which was derived from
@@ -1128,6 +1140,26 @@ hardcopy(Widget w, XtPointer client_data, XtPointer call_data)
     }
 }
 
+static void
+hardcopySVG(Widget w, XtPointer client_data, XtPointer call_data)
+{
+    NG_IGNORE(call_data);
+    NG_IGNORE(w);
+
+    lasthardcopy = (GRAPH*)client_data;
+
+    cp_vset("hcopydevtype", CP_STRING, "svg");
+
+    if (currentgraph) {
+        void* devdep = currentgraph->devdep;
+        com_hardcopy(NULL);
+        currentgraph->devdep = devdep;
+    }
+    else {
+        com_hardcopy(NULL);
+    }
+}
+
 
 static void
 killwin(Widget w, XtPointer client_data, XtPointer call_data)