Split the urscript into a header and a control loop. (#14)

The header is only appended to the UR program once, while the control loop is appended for each urcap node.
This enables the possibility to have multiple urcap nodes in one program.

Header and control loop are defined by the anchors

# HEADER_BEGIN
<header code>
# HEADER_END
<control loop code>

Co-authored-by: mahp <[email protected]>
Co-authored-by: Felix Exner <[email protected]>

README.md

@@ -16,3 +16,22 @@ To enable external control of a UR robot from a remote PC, this URcap must be in
 	* Add this URcap to a program by selecting it from the side menu under the tab _URcap_.
 	* Execute the program by pressing the _play_ button in the _Program_ tab of Polyscope.
 
+### Multiple URCap nodes
+To use this URCap node multiple times in a ur program, the control script is divided into two
+scripts. After receiving the script, it is divided into a header part and a control loop part. The
+header part consist of all the function deffinitions. The header is only inserted once in the 
+program, while the control loop is inserted for each URCap node in the program tree.
+
+To be able to distinguish between header and control loop, the header part of the script should be
+encapsulated in:
+```bash
+# HEADER_BEGIN
+Here goes the header code
+# HEADER_END
+
+# NODE_CONTROL_LOOP_BEGINS
+Here goes the control loop code
+# NODE_CONTROL_LOOP_ENDS
+```
+If its not possible to find either `# HEADER_BEGIN` or `# HEADER_END`, the script will not be
+divided into two scripts and it will not be possible to have multiple URCap nodes in one program.

src/main/java/com/fzi/externalcontrol/impl/ExternalControlInstallationNodeContribution.java

@@ -37,13 +37,14 @@ public class ExternalControlInstallationNodeContribution implements Installation
   private static final String HOST_IP = "host_ip";
   private static final String PORT_NR = "port_nr";
   private static final String NAME = "name";
-  private String urScriptProgram = "";
   private static final String DEFAULT_IP = "192.168.56.1";
   private static final String DEFAULT_PORT = "50002";
   private static final String DEFAULT_NAME = DEFAULT_IP;
   private DataModel model;
   private final ExternalControlInstallationNodeView view;
   private final KeyboardInputFactory keyboardFactory;
+  private RequestProgram sender;
+  private boolean programRequested;
 
   public ExternalControlInstallationNodeContribution(InstallationAPIProvider apiProvider,
       ExternalControlInstallationNodeView view, DataModel model) {
@@ -65,8 +66,7 @@ public boolean isDefined() {
 
   @Override
   public void generateScript(ScriptWriter writer) {
-    // Make sure the program gets requested at least once
-    urScriptProgram = "";
+    programRequested = false;
   }
 
   // IP helper functions
@@ -168,11 +168,17 @@ public void onOk(String value) {
     };
   }
 
-  public String getUrScriptProgram() {
-	if (urScriptProgram == "") {
-	  RequestProgram sender = new RequestProgram(getHostIP(), getCustomPort());
-	  urScriptProgram = sender.sendCommand("request_program\n");
-	}
-    return urScriptProgram;
+  public String getControlLoop(ScriptWriter writer) {
+    if (programRequested == false) {
+      // Request and split the program
+      sender = new RequestProgram(getHostIP(), getCustomPort());
+      sender.requestAndSplitProgram();
+
+      // Append header to the ur program.
+      writer.appendRaw(sender.getHeader());
+
+      programRequested = true;
+    }
+    return sender.getControlLoop();
   }
 }

src/main/java/com/fzi/externalcontrol/impl/ExternalControlProgramNodeContribution.java

@@ -79,8 +79,8 @@ public boolean isDefined() {
 
   @Override
   public void generateScript(ScriptWriter writer) {
-    String urScriptProgram = getInstallation().getUrScriptProgram();
-    writer.appendRaw(urScriptProgram);
+    String controlLoop = getInstallation().getControlLoop(writer);
+    writer.appendRaw(controlLoop);
   }
 
   private ExternalControlInstallationNodeContribution getInstallation() {

src/main/java/com/fzi/externalcontrol/impl/RequestProgram.java

@@ -37,13 +37,33 @@ public class RequestProgram {
   private final String hostIp;
   // custom port
   private final int portNr;
+  // header of the requested program
+  private String header;
+  // control loop of the requested program
+  private String controlLoop;
 
   /*
    * Default constructor
    */
   public RequestProgram(String hostIp, String portNr) {
     this.hostIp = hostIp;
     this.portNr = Integer.parseInt(portNr);
+    this.header = "";
+    this.controlLoop = "";
+  }
+
+  public void requestAndSplitProgram() {
+    String program = sendCommand("request_program\n");
+    // Split program into header and control loop
+    splitProgram(program);
+  }
+
+  public String getHeader() {
+    return this.header;
+  }
+
+  public String getControlLoop() {
+    return this.controlLoop;
   }
 
   public String sendCommand(String command) {
@@ -89,4 +109,36 @@ public String sendCommand(String command) {
     }
     return result;
   }
+
+  public void splitProgram(String program) {
+    this.header = "";
+    this.controlLoop = "";
+    Boolean headerEndFound = false;
+    Boolean headerBeginFound = false;
+    String[] programArray = program.split("\n");
+
+    for (int it = 0; it < programArray.length; ++it) {
+      if (programArray[it].matches("(\\p{Zs}*)# HEADER_BEGIN(\\p{Zs}*)")) {
+        headerBeginFound = true;
+        this.header += programArray[it] + "\n";
+      }
+      else if (programArray[it].matches("(\\p{Zs}*)# HEADER_END(\\p{Zs}*)") && headerBeginFound) {
+        headerEndFound = true;
+        headerBeginFound = false;
+        this.header += programArray[it] + "\n";
+      }
+      else if (headerBeginFound) {
+        this.header += programArray[it] + "\n";
+      }
+      else if (headerEndFound) {
+        this.controlLoop += programArray[it] + "\n";
+      }
+    }
+
+    if (headerEndFound == false) {
+      System.out.println("Unable to find anchors defining header, the program will not be split");
+      this.header = "";
+      this.controlLoop = program;
+    }
+  }
 }