View element android - android

I would like to show a chart that I create with GraphicalView from AChartEngineLibrary in another View element.
I should do that because I use the other view element to receive messages that I use to update the chart.
I don't know how to show a view element in aview element.
Can someone help me?
Thank You in advance.

without third parties like AChartEngineLibrary also we will implement charts. below is the sample code for without third party this is the piechart example
package com.rmn.piechart;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
public class AndroidPieChartActivity extends Activity {
/** Called when the activity is first created. */
float values[]={200,400,200,500,300};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout linear=(LinearLayout) findViewById(R.id.linear);
values=calculateData(values);
MyGraphview graphView = new MyGraphview(this, values);
graphView.setPadding(50, 30, 35, 0);
linear.addView(graphView,LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT);
}
private float[] calculateData(float[] data) {
float total=0;
for(int i=0;i<data.length;i++)
{
total+=data[i];
}
for(int i=0;i<data.length;i++)
{
data[i]=360*(data[i]/total);
}
return data;
}
public class MyGraphview extends View
{
private Paint paint=new Paint(Paint.ANTI_ALIAS_FLAG);
private float[] value_degree;
private int[] COLORS={Color.BLUE,Color.GREEN,Color.GRAY,Color.CYAN,Color.RED};
RectF rectf = new RectF (10, 10, 200, 200);
int temp=0;
public MyGraphview(Context context, float[] values) {
super(context);
value_degree=new float[values.length];
for(int i=0;i<values.length;i++)
{
value_degree[i]=values[i];
}
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (int i = 0; i < value_degree.length; i++) {//values2.length; i++) {
if (i == 0) {
paint.setColor(COLORS[i]);
canvas.drawArc(rectf, 0, value_degree[i], true, paint);
}
else
{
temp += (int) value_degree[i - 1];
paint.setColor(COLORS[i]);
canvas.drawArc(rectf, temp, value_degree[i], true, paint);
}
}
}
}
}

Related

draw arrows with Path in Android

I read the article on http://www.curious-creature.org/2013/12/21/android-recipe-4-path-tracing/
Trying to draw arrows with Path which mentioned in the article, but with the following code, I got the half arrow, I already read articles about how to draw arrows on android. This question is more about "what's wrong with the following code." Thanks in advance.
package com.example.linepractice;
import android.os.Bundle;
import android.app.Activity;
import android.view.LayoutInflater;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
PracticeLineView pl = new PracticeLineView(this);
LayoutInflater mInflater = LayoutInflater.from(this);
LinearLayout mainView = (LinearLayout) mInflater.inflate(R.layout.activity_main, null);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.setMargins(120, 120, 120, 120);
pl.setLayoutParams(params);
mainView.addView(pl);
setContentView(mainView);
}
}
package com.example.linepractice;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.view.View;
public class PracticeLineView extends View {
private Paint mPaint;
public PracticeLineView(Context context) {
super(context);
mPaint = new Paint();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.translate(getPaddingLeft(), getPaddingTop() - getPaddingBottom());
canvas.drawPath(makeArrow(140,140), mPaint);
}
private static Path makeArrow(float length, float height) {
Path p = new Path();
p.moveTo(-2.0f, -height / 2.0f);
p.lineTo(length, 0.0f);
p.lineTo(-2.0f, height / 2.0f);
p.lineTo(-2.0f, -height / 2.0f);
p.close();
return p;
}
}
pic:
private static Path makeArrow(float length, float height) {
Path p = new Path();
p.moveTo(-2.0f, 0.0f);
p.lineTo(length, height / 2.0f);
p.lineTo(-2.0f, height);
p.lineTo(-2.0f, 0.0f);
p.close();
return p;
}

Android calculate the area of polygon using canvas drawing(not maps)

I use this codes for draw a polygon on a canvas. But I want to calculate the area of polygon. Of course give the measurements of each line. I see a lot of example on maps but ı don't convert/adapt on canvas. Can anyone showing a way or method ?
Thanks in advance.
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Point;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class MainActivity extends Activity
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(new DrawingView(MainActivity.this));
}
class DrawingView extends SurfaceView
{
private SurfaceHolder surfaceHolder;
private final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
private List<Point> pointsList = new ArrayList<Point>();
public DrawingView(Context context)
{
super(context);
surfaceHolder = getHolder();
paint.setColor(Color.BLACK);
paint.setStyle(Style.FILL);
}
#Override
public boolean onTouchEvent(MotionEvent event)
{
if (event.getAction() == MotionEvent.ACTION_DOWN)
{
if (surfaceHolder.getSurface().isValid())
{
// Add current touch position to the list of points
pointsList.add(new Point((int) event.getX(), (int) event.getY()));
// Get canvas from surface
Canvas canvas = surfaceHolder.lockCanvas();
// Clear screen
canvas.drawColor(Color.WHITE);
// Iterate on the list
for (int i = 0; i < pointsList.size(); i++)
{
Point current = pointsList.get(i);
Point first = pointsList.get(0);
// Draw points
canvas.drawCircle(current.x, current.y, 5, paint);
// Draw line with next point (if it exists)
if (i + 1 < pointsList.size())
{
Point next = pointsList.get(i + 1);
canvas.drawLine(current.x, current.y, next.x, next.y, paint);
canvas.drawLine(next.x, next.y, first.x, first.y, paint);
c
}
}
// Release canvas
surfaceHolder.unlockCanvasAndPost(canvas);
}
}
return false;
}
}
}
Here's a method for calculating the area of a polygon.
for (int i = 0; i < points.size(); i++) {
float addX = points.get(i).x;
float addY = points.get(i == points.size() - 1 ? 0 : i + 1).y;
float subX = points.get(i == points.size() - 1 ? 0 : i + 1).x;
float subY = points.get(i).y;
total += (addX * addY * 0.5);
total -= (subX * subY * 0.5);
}
return Math.abs(total);

What is wrong with this android code?

When I try to run this code I get an error in the view activity stating that void is an invalid type for the function "protected void onDraw(Canvas canvas)".
This is the main activity
package com.example.crazyeights;
import android.app.Activity;
import android.os.Bundle;
public class CrazyEightsActivity extends Activity
{
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
CrazyEightsView myView = new CrazyEightsView(this);
setContentView(myView);
}
}
This is the View activity
package com.example.crazyeights;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;
public class CrazyEightsView extends View
{
private Paint redPaint;
private int circleX;
private int circleY;
private float radius;
public CrazyEightsView(Context context)
{
super(context);
redPaint = new Paint();
redPaint.setAntiAlias(true);
redPaint.setColor(Color.RED);
circleX = 100;
circleY = 100;
radius = 30;
This is where the error occurs.
#Override
protected void onDraw(Canvas canvas)
{
canvas.drawCircle(circleX, circleY, radius, redPaint);
}
}
}
Move onDraw out of the constructor.
public CrazyEightsView(Context context)
{
super(context);
redPaint = new Paint();
redPaint.setAntiAlias(true);
redPaint.setColor(Color.RED);
circleX = 100;
circleY = 100;
radius = 30;
} // <-- put } here
#Override
protected void onDraw(Canvas canvas)
{
canvas.drawCircle(circleX, circleY, radius, redPaint);
}
//} <-- used to be here

Android - Draw a rect using canvas which should raise from bottom

I want to draw a stack which should raise from the bottom. For example the stack height is 400, from the height 10 it should grow till it reaches 400.
I want to do this using paint and canvas.
I don't want to do it with image view/bitmap and scale animation.
Is it possible to do this with canvas and paint? if so how to achieve it?
Thanks in advance.
You could try using something like this (have not tested myself):
Paint paint = new Paint();
paint.setColor(Color.BLACK);
for(int i = 10; i < 400; i = i + 10)
{
try
{
// To slow the for loop down, can change 100 accordingly or remove altogther
Thread.sleep(100);
}
catch (InterruptedException e)
{
e.printStackTrace();
}
canvas.drawRect(0, i, 10, 0, paint); // this will make 10 x 10 square starting from bottom
invalidate();
}
What ever you do with canvas, even if you try for loop or invalidate, sleep, after all its drawing the shape in single stretch. I found the result in following way. May be it would be helpful for someone else, so adding the code here.
import android.os.Bundle;
import android.os.CountDownTimer;
import android.app.Activity;
import android.graphics.Color;
import android.util.Log;
import android.view.Menu;
public class AndroidDraw extends Activity {
private DrawView drawView;
private int height = 300;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_android_draw);
CountDownTimer timer = new CountDownTimer(2000, 50) {
#Override
public void onTick(long millisUntilFinished) {
height = height - 10;
drawView = new DrawView(AndroidDraw.this, height);
drawView.setBackgroundColor(Color.WHITE);
setContentView(drawView);
}
#Override
public void onFinish() {
}
};
timer.start();
}
}
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;
public class DrawView extends View {
Paint paint = new Paint();
private int height;
public DrawView(Context context, int height) {
super(context);
this.height = height;
}
#Override
public void onDraw(Canvas canvas) {
paint.setColor(Color.RED);
canvas.drawRect(30, height, 60, 300, paint );
}
}

Only one view is displayed in Android

I am new to Android. When i run this code, only one circle is displayed. If i remove view1, then view2 is displayed. but they are never displayed together!!! why is that?
Any help would be appreciated.
thanks
package com.dots;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
public class Dots1Activity extends Activity
{
private static final String TAG = "DotsActivity";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.HORIZONTAL);
TextView label = new TextView(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
label.setText("Click the circle!");
CustomDrawableView view1 = new CustomDrawableView(this, 100, 100, 50, Color.RED);
CustomDrawableView view2 = new CustomDrawableView(this, 200, 200, 25, Color.GREEN);
CustomDrawableView view3 = new CustomDrawableView(this, 300, 300, 10, Color.WHITE);
ll.addView(label, layoutParams);
ll.addView(view1, layoutParams);
ll.addView(view2, layoutParams);
ll.addView(view3, layoutParams);
setContentView(ll);
}
}
class CustomDrawableView extends View implements OnClickListener{
private Context context;
private int x, y, radius, color;
public CustomDrawableView(Context context, int x, int y, int radius, int color) {
super(context);
this.context = context;
this.x = x;
this.y =y;
this.radius = radius;
this.color = color;
setOnClickListener(this);
}
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
this.setBackgroundColor(Color.LTGRAY);
Paint paint = new Paint (Paint.ANTI_ALIAS_FLAG);
paint.setColor(color);
canvas.drawCircle(x, y, radius, paint);
}
public void onClick(View v) {
Toast.makeText(this.context,
x+"-"+y+"-"+radius,
Toast.LENGTH_SHORT).show();
}
}
ll.setOrientation(LinearLayout.HORIZONTAL);
They are put next to each other. You can't see them, because your display isn't width naught. Put them in a HorizontalScrollView or make them aper VERTICAL.
I'm not sure if this takes effect here, but i found this on the Android Documentation:
Note that the framework will not draw
views that are not in the invalid
region. To force a view to draw, call
invalidate().
Try if this solves your problem (for the moment I guess).
About your Code
Something i noticed: The implemented interface for the onClickListener is View.OnClickListener:
class CustomDrawableView extends View implements View.OnClickListener{ [...] }
How to solve the Problem
I looked around on the Android Docs and found this. They mantioned the method onMeasure(), which:
Measure the view and its content to
determine the measured width and the
measured height.
So I added it to your custom CustomDrawableView-class. Unfortuandly, you can't pass the super.onMeasure()-method simple integers, you'll need to decode them first, using the View.MeasureSpec-class:
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
super.onMeasure(View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY));
}
In the Example, I set both width and height to 100px. Also, I did some other improvements on your code:
Dots1Activity-class
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.widget.LinearLayout;
import android.widget.TextView;
public class Dots1Activity extends Activity
{
private static final String TAG = "DotsActivity";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
TextView label = new TextView(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
label.setText("Click the circle!");
CustomDrawableView view1 = new CustomDrawableView(this, 50, 50, 50, Color.RED);
CustomDrawableView view2 = new CustomDrawableView(this, 75, 75, 25, Color.GREEN);
CustomDrawableView view3 = new CustomDrawableView(this, 85, 85, 10, Color.WHITE);
ll.addView(label, layoutParams);
ll.addView(view1, layoutParams);
ll.addView(view2, layoutParams);
ll.addView(view3, layoutParams);
setContentView(ll);
}
}
CustomDrawableView-class
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;
import android.widget.Toast;
class CustomDrawableView extends View implements View.OnClickListener{
private Context context;
private int x, y, radius, color;
public CustomDrawableView(Context context, int x, int y, int radius, int color) {
super(context);
this.context = context;
this.x = x;
this.y =y;
this.radius = radius;
this.color = color;
setOnClickListener(this);
}
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(color);
canvas.drawCircle(x, y, radius, paint);
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
super.onMeasure(View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(100, View.MeasureSpec.EXACTLY));
}
public void onClick(View v) {
Toast.makeText(this.context,
x+"-"+y+"-"+radius,
Toast.LENGTH_SHORT).show();
}
}
This code compiles, shows all the circles and the onClick-Event works, too.
Although I have to say it was a bit of a challenge and I'm grateful for it.
change the orientation of you layout to vertical like this :
ll.setOrientation(LinearLayout.VERTICAL);

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