run gnuplot in interactive mode

Author: wesley2012

base/src/main/java/com/panayotis/gnuplot/GNUPlot.java

@@ -354,6 +354,27 @@ public void setPersist(boolean ispersist) {
         exec.setPersist(ispersist);
     }
 
+    /**
+     * Run gnuplot in interactive mode
+     *
+     * @author wesley
+     *
+     * @param interactive
+     */
+    public void setInteractive(boolean interactive) {
+        exec.setInteractive(interactive);
+    }
+
+    /**
+     * Close an interactive plot.
+     * Currently this method can only end the gnuplot process, but is unable to close the graph window. Need your help!
+     *
+     * @author wesley
+     */
+    public void close(){
+        exec.close();
+    }
+
     /**
      * Set gnuplot parameters to another set of parameters.
      *

base/src/main/java/com/panayotis/gnuplot/GNUPlotExec.java

@@ -37,9 +37,14 @@ class GNUPlotExec {
     private static final transient String DEFAULT_PATH = FileUtils.findPathExec();
     private transient String gnuplotexec;
     private boolean ispersist;
+    private boolean interactive;
     private final static String[] persistcommand = {"path", "file", "-persist"};
+    private final static String[] persist_interactive = {"path", "file", "-", "-persist"};
     private final static String[] nopersist = {"path", "file"};
 
+    private Process proc;
+    private String tmpfile;
+
     /**
      * Create a new GNUPlotExec object with defaultΩ gnuplot path. Under POSIX
      * environment, it is able to automatically find gnuplot executable in the
@@ -125,7 +130,7 @@ void plot(GNUPlotParameters par, GNUPlotTerminal terminal) throws GNUPlotExcepti
              */
             String[] command;
             if (ispersist)
-                command = persistcommand;
+                command = interactive ? persist_interactive : persistcommand;
             else
                 command = nopersist;
             command[0] = getGNUPlotPath();
@@ -177,6 +182,12 @@ public void run() {
             };
             out_thread.start();
 
+            if (interactive){
+                this.proc = proc;
+                this.tmpfile = command[1];
+                return;
+            }
+
             try {
                 proc.waitFor(); // wait for process to finish
                 out_thread.join();  // wait for output (terminal related) thread to finish
@@ -218,6 +229,31 @@ void setPersist(boolean persist) {
         ispersist = persist;
     }
 
+    public void setInteractive(boolean interactive) {
+        this.interactive = interactive;
+    }
+
+    public void close(){
+        if (proc == null){
+            return;
+        }
+        try {
+            proc.getOutputStream().close();
+            proc.getInputStream().close();
+            proc.getErrorStream().close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        try {
+            proc.waitFor(); // wait for process to finish
+        } catch (InterruptedException ex) {
+            throw new GNUPlotException("Interrupted execution of gnuplot");
+        }
+        new File(tmpfile).delete();
+        proc.destroy();
+        proc = null;
+    }
+
     private class Messages {
 
         String output = "";

base/src/test/java/com/panayotis/gnuplot/demo/BaseDemo.java

@@ -56,10 +56,10 @@ public static void main(String[] args) {
 //        defaultTerminal(path);
 //        EPSTerminal(path);
 //        SVGTerminal(path);
-        JPlotTerminal(path);
+        //JPlotTerminal(path);
         //serialization(defaultTerminal(path));
         //file();
-
+        interactive();
     }
 
     /* This is a very simple plot to demonstrate JavaPlot graphs */
@@ -189,4 +189,17 @@ private static void file() {
             ex.printStackTrace();
         }
     }
+
+    private static void interactive() {
+        JavaPlot p = new JavaPlot(true);
+        p.addPlot("sin(x)*y");
+        p.setInteractive(true);
+        p.plot();
+        try {
+            Thread.sleep(10000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        p.close();
+    }
 }