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POHow do I call set changes in a "Custom View" by calling a function from a button.?
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I have created a Custom View component and my layout file consists of a button and the CustomView.Whenever I press the button,I want to update the Filename in the CustomView class.This occurs by invoking the set_file method of the customview and the set_file method is called in the function perform();.However I get an error while doing so. HERE are my 3 classes. <code>TestActivity.java</code> package com.android.pack; import java.net.URISyntaxException; <pre><code>import android.app.Activity; import android.content.Context; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup.LayoutParams; import android.widget.Button; import android.widget.LinearLayout; import android.widget.Toast; public class TestActivity extends Activity { /** Called when the activity is first created. */ int height; int weight; Button select; customview cView; String path=""; String pathchk=""; String temp=""; private static final int FILE_SELECT_CODE = 0; public void perform() { cView.set_file(pathchk); cView.postInvalidate(); } public void showFileChooser(View v) { Intent intent = new Intent(Intent.ACTION_GET_CONTENT); intent.setType("*/*"); intent.addCategory(Intent.CATEGORY_OPENABLE); try { startActivityForResult( Intent.createChooser(intent, "Select a File to Upload"), FILE_SELECT_CODE); } catch (android.content.ActivityNotFoundException ex) { // Potentially direct the user to the Market with a Dialog Toast.makeText(this, "Please install a File Manager.", Toast.LENGTH_SHORT).show(); } } protected void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode) { case FILE_SELECT_CODE: if (resultCode == RESULT_OK) { // Get the Uri of the selected file Uri uri = data.getData(); Log.v("check", "File Uri: " + uri.toString()); // Get the path try { path = FileUtils.getPath(this, uri); pathchk=path.substring(12); perform(); } catch (URISyntaxException e) { // TODO Auto-generated catch block Log.v("error", "File Path: "+pathchk); } Log.v("check", "File Path: "+path); // Get the file instance // File file = new File(path); // Initiate the upload } break; } super.onActivityResult(requestCode, resultCode, data); } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LayoutInflater li = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE); View v=li.inflate(R.layout.main, null); cView = (customview)findViewById(R.id.customview1); LinearLayout ll = new LinearLayout(this); ll.setOrientation(LinearLayout.VERTICAL); select=(Button)findViewById(R.id.button1); // select.setText("Select a File"); /* select.setOnClickListener(new Button.OnClickListener(){ @Override public void onClick(View v) { // TODO Auto-generated method stub showFileChooser(); Toast.makeText(getApplicationContext(), "The File "+path+" is loaded",Toast.LENGTH_LONG); } }); */ // LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams( // LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT); //ll.addView(select, new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); //ll.addView(cView, layoutParams); setContentView(R.layout.main); } } </code></pre> customview.java <pre><code>package com.android.pack; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileReader; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.StringTokenizer; import android.app.AlertDialog; import android.content.Context; import android.content.DialogInterface; import android.gesture.Gesture; import android.gesture.GesturePoint; import android.gesture.GestureStroke; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Path; import android.graphics.Point; import android.os.Environment; import android.util.AttributeSet; import android.util.Log; import android.view.View; import android.view.View.* ; import android.widget.Button; import android.widget.Toast; public class customview extends View implements OnClickListener { ArrayList<GesturePoint> child; ArrayList<Point> pnts; Point pnt=new Point(); File myFile; BufferedReader br; FileInputStream in; InputStreamReader fin; GestureStroke gest; Gesture my_final=new Gesture(); String Token; long Time=30000000; int flag=0; boolean line=true; boolean points=true; Button b1; int height; int weight; String Filename=""; ArrayList<Path> paths; Path mypath; Paint mypaint=new Paint();// public void set_file(String a)// to set the File { Filename=a; //clear_screen(); } public customview(Context context) { super(context); this.setOnClickListener(this); mypaint.setColor(Color.RED); mypaint.setAntiAlias(true); mypaint.setStyle(Paint.Style.STROKE); mypaint.setStrokeWidth(5); myFile=Environment.getExternalStorageDirectory(); } public customview(Context context,AttributeSet att) { super(context,att); this.setOnClickListener(this); mypaint.setColor(Color.RED); mypaint.setAntiAlias(true); mypaint.setStyle(Paint.Style.STROKE); mypaint.setStrokeWidth(5); myFile=Environment.getExternalStorageDirectory(); } public void make_shape() { paths=new ArrayList<Path>(); pnts=new ArrayList<Point>(); height=this.getHeight(); weight=this.getWidth(); Log.v("Main_custom_height",height+""); Log.v("Main_custom_weight",weight+""); try { File file = new File(myFile,Filename); br=new BufferedReader(new FileReader(file)); String read; while((read=br.readLine())!=null) { //Toast.makeText(Create_pathActivity.this,read,Toast.LENGTH_SHORT).show(); if(read.equals(".PEN_UP")) { flag=0; gest=new GestureStroke(child); mypath=gest.getPath(); paths.add(mypath); my_final.addStroke(gest); } if(flag==1) { StringTokenizer st = new StringTokenizer(read); for(int i=0;i<=2;i++) { if(i==0) { Token=st.nextToken(); pnt.x=Integer.parseInt(Token); //pnt.x=pnt.x+200; //pnt.x=pnt.x/5; Log.v("PointX",Token); } if(i==1) { Token=st.nextToken(); pnt.y=Integer.parseInt(Token); //pnt.y=pnt.y+165; //pnt.y=pnt.y/5; Log.v("PointY",Token); } if(i==2) { Time=Time+10; GesturePoint temp=new GesturePoint(pnt.x,pnt.y,Time); child.add(temp); } } Point p=new Point(); p.x=pnt.x; p.y=pnt.y; pnts.add(p); } if(read.equals(".PEN_DOWN")) { flag=1; child=new ArrayList<GesturePoint>(); } } }catch (Exception e) { } } protected void onDraw(Canvas canvas) { if(points==true && line==false) { for (Point point : pnts) { canvas.drawCircle(point.x, point.y, 3,mypaint); } } if(points==false && line==true) { for( int i=0;i<paths.size();i++) { canvas.drawPath(paths.get(i), mypaint); } } } public void scale() { int S_width = 320, S_height = 410, width, height, DiffW, DiffH; int max_x = 0, max_y = 0, min_x = 320, min_y = 410; int new_x, new_y; int i; float scale; for(i=0; i<pnts.size(); i++) { if( pnts.get(i).x > max_x ) max_x = pnts.get(i).x; if( pnts.get(i).x < min_x ) min_x = pnts.get(i).x; if( pnts.get(i).y > max_y ) max_y = pnts.get(i).y; if( pnts.get(i).y < min_y ) min_y = pnts.get(i).y; } width = max_x - min_x; height = max_y - min_y; DiffW = Math.abs(S_width - width); DiffH = Math.abs(S_height - height); if( DiffW > DiffH ) scale = width/300; else scale = height/390; //scaling for(i=0; i<pnts.size(); i++) { pnts.get(i).x /= scale; pnts.get(i).y /= scale; } new_x = max_x - 10; new_y = min_y - 10; //top-left shifting for(i=0; i<pnts.size(); i++) { pnts.get(i).x -= new_x; pnts.get(i).y -= new_y; } } @Override public void onClick(View v) { // TODO Auto-generated method stub if(Filename.equals("")) { Toast.makeText(getContext(),"Select a file ist", Toast.LENGTH_SHORT); return; } make_shape(); AlertDialog.Builder builder = new AlertDialog.Builder(getContext()); builder.setCancelable(true); builder.setTitle("Draw a line or a path"); builder.setInverseBackgroundForced(true); builder.setPositiveButton("Line", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { line=true; points=false; invalidate(); } }); builder.setNegativeButton("Point", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { line=false; points=true; //scale(); invalidate(); } }); AlertDialog alert = builder.create(); alert.show(); } } **FileUtils.java** package com.android.pack; import java.net.URISyntaxException; import android.content.Context; import android.database.Cursor; import android.net.Uri; public class FileUtils { public static String getPath(Context context, Uri uri) throws URISyntaxException { if ("content".equalsIgnoreCase(uri.getScheme())) { String[] projection = { "_data" }; Cursor cursor = null; try { cursor = context.getContentResolver().query(uri, projection, null, null, null); int column_index = cursor .getColumnIndexOrThrow("_data"); if (cursor.moveToFirst()) { return cursor.getString(column_index); } } catch (Exception e) { // Eat it } } else if ("file".equalsIgnoreCase(uri.getScheme())) { return uri.getPath(); } return null; } } </code></pre> and here is my main.xml file <pre><code><?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <com.android.pack.customview android:id="@+id/customview1" android:layout_width="wrap_content" android:layout_height="419dp" android:layout_weight="0.63" /> <Button android:id="@+id/button1" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="select a file" android:onClick="showFileChooser"/> </LinearLayout> </code></pre> My log cat is <pre><code>01-09 12:04:42.038: D/szipinf(4990): Initializing inflate state 01-09 12:04:42.248: D/dalvikvm(4990): GC_CONCURRENT freed 281K, 50% free 2860K/5639K, external 0K/0K, paused 4ms+8ms 01-09 12:04:48.668: V/check(4990): File Uri: content://org.openintents.cmfilemanager/mimetype//mnt/sdcard/points.txt 01-09 12:04:48.698: D/AndroidRuntime(4990): Shutting down VM 01-09 12:04:48.698: W/dalvikvm(4990): threadid=1: thread exiting with uncaught exception (group=0x40018560) 01-09 12:04:48.698: E/AndroidRuntime(4990): FATAL EXCEPTION: main 01-09 12:04:48.698: E/AndroidRuntime(4990): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=0, result=-1, data=Intent { act=android.intent.action.VIEW dat=content://org.openintents.cmfilemanager/mimetype//mnt/sdcard/points.txt }} to activity {com.android.pack/com.android.pack.TestActivity}: java.lang.NullPointerException 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.app.ActivityThread.deliverResults(ActivityThread.java:2653) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.app.ActivityThread.handleSendResult(ActivityThread.java:2695) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.app.ActivityThread.access$2000(ActivityThread.java:123) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:969) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.os.Handler.dispatchMessage(Handler.java:99) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.os.Looper.loop(Looper.java:130) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.app.ActivityThread.main(ActivityThread.java:3835) 01-09 12:04:48.698: E/AndroidRuntime(4990): at java.lang.reflect.Method.invokeNative(Native Method) 01-09 12:04:48.698: E/AndroidRuntime(4990): at java.lang.reflect.Method.invoke(Method.java:507) 01-09 12:04:48.698: E/AndroidRuntime(4990): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847) 01-09 12:04:48.698: E/AndroidRuntime(4990): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605) 01-09 12:04:48.698: E/AndroidRuntime(4990): at dalvik.system.NativeStart.main(Native Method) 01-09 12:04:48.698: E/AndroidRuntime(4990): Caused by: java.lang.NullPointerException 01-09 12:04:48.698: E/AndroidRuntime(4990): at com.android.pack.TestActivity.perform(TestActivity.java:32) 01-09 12:04:48.698: E/AndroidRuntime(4990): at com.android.pack.TestActivity.onActivityResult(TestActivity.java:64) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.app.Activity.dispatchActivityResult(Activity.java:3908) 01-09 12:04:48.698: E/AndroidRuntime(4990): at android.app.ActivityThread.deliverResults(ActivityThread.java:2649) 01-09 12:04:48.698: E/AndroidRuntime(4990): ... 11 more </code></pre> Appreciate any help!!
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How do I call set changes in a "Custom View" by calling a function from a button.?
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