How can achieve this custom view wave animation? - java

I'm trying to achieve this custom wave animation with circle in the middle of the wave.
Below is my custom view. It runs in a different direction and the draw has a line in the middle of the wave that results in a bad UX.
I try to follow some related tutorials but I cannot get the same animation.
If there is any library o code sample to follow it could help me a lot.
Thanks.
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.Region;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.LinearInterpolator;
import com.guille.stressmeterapp.R;
import org.jetbrains.annotations.Nullable;
public class WaveCustomView extends View {
private int mWidth = 0;
private int mHeight = 0;
private Path path;
private Paint paint;
private int waveHeight = 300;
private int waveWidth = 600;
private int originalY = 750;
private Region region;
private int dx = 0;
private Bitmap mBitmap;
private int animationDuration = 3000;
public WaveCustomView(Context context) {
super(context, null);
initUi();
}
public WaveCustomView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs, 0);
initUi();
}
public WaveCustomView(Context context, #Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initUi();
}
private void initUi() {
paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(Color.parseColor("#000000"));
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(15);
path = new Path();
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.circle);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int width;
int height;
if (widthMode == MeasureSpec.EXACTLY) {
width = widthSize;
} else {
int desired = (int) (getPaddingLeft() + getPaddingRight());
width = desired;
}
if (heightMode == MeasureSpec.EXACTLY) {
height = heightSize;
} else {
int desired = (int) (getPaddingTop() + getPaddingBottom());
height = desired;
}
mWidth = width;
mHeight = height;
waveWidth = mWidth / 2;
setMeasuredDimension(width, height);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawPath(path, paint);
setDrawData();
Rect bounds = region.getBounds();
if (bounds.top < originalY) {
canvas.drawBitmap(mBitmap, bounds.right - (mBitmap.getWidth() >> 1), bounds.top - (mBitmap.getHeight() >> 1), paint);
} else {
canvas.drawBitmap(mBitmap, bounds.right - (mBitmap.getWidth() >> 1), bounds.bottom - (mBitmap.getHeight() >> 1), paint);
}
}
private void setDrawData() {
path.reset();
int halfWaveWidth = waveWidth / 2;
path.moveTo(-waveWidth + dx, originalY);
for (int i = -waveWidth; i < mWidth + waveWidth; i = i + waveWidth) {
path.rQuadTo(halfWaveWidth >> 1, -waveHeight, halfWaveWidth, 0);
path.rQuadTo(halfWaveWidth >> 1, waveHeight, halfWaveWidth, 0);
}
region = new Region();
Region clip = new Region((int) (mWidth / 2 - 0.1), 0, mWidth / 2, mHeight * 2);
region.setPath(path, clip);
path.close();
}
public void startAnimate() {
ValueAnimator animator = ValueAnimator.ofFloat(0, 1);
animator.setRepeatCount(ValueAnimator.INFINITE);
animator.setInterpolator(new LinearInterpolator());
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
float factor = (float) valueAnimator.getAnimatedValue();
dx = (int) ((waveWidth) * factor);
invalidate();
}
});
animator.setDuration(animationDuration);
animator.start();
}

Your code looks OK. Just remove this line from setDrawData method.
path.close();
This line closes path. It means it connect path begginnig with path end. That's why you see line in the middle of the wave.
Here is result without middle line:
If you want to change the direction of animation just change sign of dx variable. Change this:
dx = (int) ((waveWidth) * factor);
To this:
dx = - (int) (waveWidth * factor);
Or instead of this:
path.moveTo(-waveWidth + dx, originalY);
Do this:
path.moveTo(-waveWidth - dx, originalY);
Final result:

Related

how do I build hexagons as buttons on android studio?

I'm developing a "settlers of catan" app and I got a big graphic problem: the game board contains a hexagons which have to be buttons. I searched on youtube but I didn't find any way to draw a hex button.
Does anyone know how to build a hexagon button?
related to : How to draw hexagons in android? Try this class :
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Path;
import android.graphics.Region;
import android.util.AttributeSet;
import android.view.View;
public class HexagonMaskView extends View {
private Path hexagonPath;
private Path hexagonBorderPath;
private float radius;
private float width, height;
private int maskColor;
public HexagonMaskView(Context context) {
super(context);
init();
}
public HexagonMaskView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public HexagonMaskView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
hexagonPath = new Path();
hexagonBorderPath = new Path();
maskColor = 0xFF01FF77;
}
public void setRadius(float r) {
this.radius = r;
calculatePath();
}
public void setMaskColor(int color) {
this.maskColor = color;
invalidate();
}
private void calculatePath() {
float triangleHeight = (float) (Math.sqrt(3) * radius / 2);
float centerX = width/2;
float centerY = height/2;
hexagonPath.moveTo(centerX, centerY + radius);
hexagonPath.lineTo(centerX - triangleHeight, centerY + radius/2);
hexagonPath.lineTo(centerX - triangleHeight, centerY - radius/2);
hexagonPath.lineTo(centerX, centerY - radius);
hexagonPath.lineTo(centerX + triangleHeight, centerY - radius/2);
hexagonPath.lineTo(centerX + triangleHeight, centerY + radius/2);
hexagonPath.moveTo(centerX, centerY + radius);
float radiusBorder = radius - 5;
float triangleBorderHeight = (float) (Math.sqrt(3) * radiusBorder / 2);
hexagonBorderPath.moveTo(centerX, centerY + radiusBorder);
hexagonBorderPath.lineTo(centerX - triangleBorderHeight, centerY + radiusBorder/2);
hexagonBorderPath.lineTo(centerX - triangleBorderHeight, centerY - radiusBorder/2);
hexagonBorderPath.lineTo(centerX, centerY - radiusBorder);
hexagonBorderPath.lineTo(centerX + triangleBorderHeight, centerY - radiusBorder/2);
hexagonBorderPath.lineTo(centerX + triangleBorderHeight, centerY + radiusBorder/2);
hexagonBorderPath.moveTo(centerX, centerY + radiusBorder);
invalidate();
}
#Override
public void onDraw(Canvas c){
super.onDraw(c);
c.clipPath(hexagonBorderPath, Region.Op.DIFFERENCE);
c.drawColor(Color.WHITE);
c.save();
c.clipPath(hexagonPath, Region.Op.DIFFERENCE);
c.drawColor(maskColor);
c.save();
}
// getting the view size and default radius
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
width = MeasureSpec.getSize(widthMeasureSpec);
height = MeasureSpec.getSize(heightMeasureSpec);
radius = height / 2 - 10;
calculatePath();
}
}

how to draw wave form in android activity

i have sample code for draw line. i need line draw point by point for run time. But now i got line after execution only showing activity. But, i need to start activity and show the line point by point i have done this concept in java sample code also attached check it.
Sample code is here
public class ImgDraw extends ActionBarActivity {
ImageView drawingImageView;
Handler mHandlerAnimation = null;
Runnable mRunnableAnimation = null;
Canvas canvas;
int startx = 0, starty = 0, endx = 0, endy = 0;
Paint paint;
Bitmap bitmap;
int width, height;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_imgdraw);
drawingImageView = (ImageView) findViewById(R.id.DrawingImageView);
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
width = metrics.widthPixels;
height = metrics.heightPixels;
bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
canvas = new Canvas(bitmap);
drawingImageView.setImageBitmap(bitmap);
// Line
paint = new Paint();
paint.setColor(Color.BLACK);
paint.setStrokeWidth(3);
startx = 50;
starty = 90;
endx = 550;
endy = 90;
// canvas.drawLine(startx, starty, startx+1, endy, paint);
ImgAnimation();
}
private void ImgAnimation() {
mHandlerAnimation = new Handler();
mRunnableAnimation = new Runnable() {
public void run() {
if (endx > startx) {
canvas.drawLine(startx, starty, startx + 1, endy, paint);
startx = startx + 1;
getWindow().getDecorView().findViewById(android.R.id.content).invalidate();
} else {
bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
canvas = new Canvas(bitmap);
drawingImageView.setImageBitmap(bitmap);
startx = 50;
}
mHandlerAnimation.postDelayed(this, 5);
}
};
mHandlerAnimation.postDelayed(mRunnableAnimation, 5);
}}
Needed output format here
I worked on java project code here
public class AndroidTest extends JFrame {
static JPanel jp;
static Graphics g2d;
static int x=10;
public static void main(String[] args) {
AndroidTest a = new AndroidTest();
a.setSize(500,500);
a.setLayout(null);
a.setLocationRelativeTo(null);
a.setDefaultCloseOperation(EXIT_ON_CLOSE);
a.setVisible(true);
jp = new JPanel();
jp.setSize(450,100);
jp.setLocation(10,100);
jp.setBackground(Color.black);
jp.setVisible(true);
a.add(jp);
g2d = jp.getGraphics();
while(x<=450){
try {
Thread.sleep(10);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int k = 0; k < 10; k++) {
g2d.setColor(Color.black);
g2d.drawLine(x+k, 0 , x + k,99);
}
g2d.setColor(Color.white);
g2d.drawLine(x,50,x+1,50);
x++;
if (x == 446) {
x=10;
}
}
}}
run this code in java then i need same output in android activity
Try this
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
public class LineView extends View {
private final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
private final Paint paint1 = new Paint(Paint.ANTI_ALIAS_FLAG);
int x=0,j=0;
public LineView(Context context) {
super(context);
init();
}
public LineView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public LineView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
public void init()
{
paint.setColor(Color.BLACK);
paint1.setColor(Color.WHITE);
}
#Override
protected synchronized void onDraw(Canvas canvas)
{
super.onDraw(canvas);
canvas.drawLine(0,50,x+1,50,paint1);
if (x > getWidth()-5) {
canvas.drawRect(j, 0, j + 20, 50, paint);
j+=4;
if(j > getWidth()-5)
j=0;
}
else
{
x+=4;
}
invalidate();
}
}
the xml is
<com.example.myapplication.LineView
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="#000"/>

ClassCastException when calling constructor for custom Button class

I`m playing with some simple Android app code but there is problem related to all layouts in code.
This is error when I open layout in eclipse
The following classes could not be instantiated:
- com.android2.calculator3.view.ColorButton (Open Class, Show Error Log)
See the Error Log (Window > Show View) for more details.
Tip: Use View.isInEditMode() in your custom views to skip code when shown in Eclipse
java.lang.ClassCastException: com.android.layoutlib.bridge.android.BridgeContext cannot be cast to com.android2.calculator3.Calculator
at com.android2.calculator3.view.ColorButton.<init>(ColorButton.java:39)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0( at sun.reflect.NativeConstructorAccessorImpl.newInstance( at sun.reflect.DelegatingConstructorAccessorImpl.newInstance( at java.lang.reflect.Constructor.newInstance( at com.android.ide.eclipse.adt.internal.editors.layout.ProjectCallback.instantiateClass(ProjectCallback.java:442)
at com.android.ide.eclipse.adt.internal.editors.layout.ProjectCallback.loadView(ProjectCallback.java:194)
at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:207)
at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:132)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:806)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:782)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:809)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:782)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:809)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:782)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:809)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:782)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:809)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:782)
at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
at android.view.LayoutInflater.inflate(LayoutInflater.java:385)
And this is my code in Colorbutton.java
package com.android2.calculator3.view;
import java.util.regex.Pattern;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.Button;
import com.android2.calculator3.Calculator;
import com.android2.calculator3.EventListener;
import calculator.app.R;
/**
* Button with click-animation effect.
*/
class ColorButton extends Button {
int CLICK_FEEDBACK_COLOR;
static final int CLICK_FEEDBACK_INTERVAL = 10;
static final int CLICK_FEEDBACK_DURATION = 350;
float mTextX;
float mTextY;
long mAnimStart;
EventListener mListener;
Paint mFeedbackPaint;
Paint mHintPaint = new Paint();
Rect bounds = new Rect();
float mTextSize = 0f;
public ColorButton(Context context, AttributeSet attrs) {
super(context, attrs);
Calculator calc = (Calculator) context;
init(calc);
mListener = calc.mListener;
setOnClickListener(mListener);
setOnLongClickListener(mListener);
}
private void init(Calculator calc) {
Resources res = getResources();
CLICK_FEEDBACK_COLOR = res.getColor(R.color.magic_flame);
mFeedbackPaint = new Paint();
mFeedbackPaint.setStyle(Style.STROKE);
mFeedbackPaint.setStrokeWidth(2);
getPaint().setColor(res.getColor(R.color.button_text));
mHintPaint.setColor(res.getColor(R.color.button_hint_text));
mAnimStart = -1;
}
private void layoutText() {
Paint paint = getPaint();
if(mTextSize != 0f) paint.setTextSize(mTextSize);
float textWidth = paint.measureText(getText().toString());
float width = getWidth() - getPaddingLeft() - getPaddingRight();
float textSize = getTextSize();
if(textWidth > width) {
paint.setTextSize(textSize * width / textWidth);
mTextX = getPaddingLeft();
mTextSize = textSize;
}
else {
mTextX = (getWidth() - textWidth) / 2;
}
mTextY = (getHeight() - paint.ascent() - paint.descent()) / 2;
if(mHintPaint != null) mHintPaint.setTextSize(paint.getTextSize() * 0.8f);
}
#Override
protected void onTextChanged(CharSequence text, int start, int before, int after) {
layoutText();
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
if(changed) layoutText();
}
private void drawMagicFlame(int duration, Canvas canvas) {
int alpha = 255 - 255 * duration / CLICK_FEEDBACK_DURATION;
int color = CLICK_FEEDBACK_COLOR | (alpha << 24);
mFeedbackPaint.setColor(color);
canvas.drawRect(1, 1, getWidth() - 1, getHeight() - 1, mFeedbackPaint);
}
#Override
public void onDraw(Canvas canvas) {
if(mAnimStart != -1) {
int animDuration = (int) (System.currentTimeMillis() - mAnimStart);
if(animDuration >= CLICK_FEEDBACK_DURATION) {
mAnimStart = -1;
}
else {
drawMagicFlame(animDuration, canvas);
postInvalidateDelayed(CLICK_FEEDBACK_INTERVAL);
}
}
else if(isPressed()) {
drawMagicFlame(0, canvas);
}
CharSequence hint = getHint();
if(hint != null) {
String[] exponents = hint.toString().split(Pattern.quote("^"));
int offsetX = getContext().getResources().getDimensionPixelSize(R.dimen.button_hint_offset_x);
int offsetY = (int) ((mTextY + getContext().getResources().getDimensionPixelSize(R.dimen.button_hint_offset_y) - getTextHeight(mHintPaint,
hint.toString())) / 2)
- getPaddingTop();
float textWidth = mHintPaint.measureText(hint.toString());
float width = getWidth() - getPaddingLeft() - getPaddingRight() - mTextX - offsetX;
float textSize = mHintPaint.getTextSize();
if(textWidth > width) {
mHintPaint.setTextSize(textSize * width / textWidth);
}
for(String str : exponents) {
if(str == exponents[0]) {
canvas.drawText(str, 0, str.length(), mTextX + offsetX, mTextY - offsetY, mHintPaint);
offsetY += getContext().getResources().getDimensionPixelSize(R.dimen.button_hint_exponent_jump);
offsetX += mHintPaint.measureText(str);
}
else {
canvas.drawText(str, 0, str.length(), mTextX + offsetX, mTextY - offsetY, mHintPaint);
offsetY += getContext().getResources().getDimensionPixelSize(R.dimen.button_hint_exponent_jump);
offsetX += mHintPaint.measureText(str);
}
}
}
CharSequence text = getText();
canvas.drawText(text, 0, text.length(), mTextX, mTextY, getPaint());
}
private int getTextHeight(Paint paint, String text) {
mHintPaint.getTextBounds(text, 0, text.length(), bounds);
int height = bounds.height();
String[] exponents = text.split(Pattern.quote("^"));
for(int i = 1; i < exponents.length; i++) {
height += getContext().getResources().getDimensionPixelSize(R.dimen.button_hint_exponent_jump);
}
return height;
}
public void animateClickFeedback() {
mAnimStart = System.currentTimeMillis();
invalidate();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
boolean result = super.onTouchEvent(event);
switch(event.getAction()) {
case MotionEvent.ACTION_UP:
if(isPressed()) {
animateClickFeedback();
}
else {
invalidate();
}
break;
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_CANCEL:
mAnimStart = -1;
invalidate();
break;
}
return result;
}
}
I can not figure out whats going wrong here?
Your error log does most of the work for you:
java.lang.ClassCastException: com.android.layoutlib.bridge.android.BridgeContext cannot be cast to com.android2.calculator3.Calculator
at com.android2.calculator3.view.ColorButton.<init>(ColorButton.java:39)
Essentially, you are attempting to cast BridgeContext to Calculator, which I assume refers to this line in your constructor:
public ColorButton(Context context, AttributeSet attrs) {
super(context, attrs);
Calculator calc = (Calculator) context; //This Line
init(calc);
mListener = calc.mListener;
setOnClickListener(mListener);
setOnLongClickListener(mListener);
}
For this to work, your context argument needs to inherit from Calculator. A simple test would be:
if (context instanceof Calculator) {
Calculator calc = (Calculator) context;
} else {
Log.e("Log Tag", context.toString() + " must inherit from Calculator class");
}
or, with a try/catch block:
try {
Calculator calc = (Calculator) context;
} catch (ClassCastException e) {
Log.e("Log Tag", context.toString() + " must inherit from Calculator class");
e.printStackTrace();
}
Edit:
A possible fix for your situation could be the following amendments to your constructor:
public ColorButton(Context context, AttributeSet attrs, Caculator calculator) {
super(context, attrs);
Calculator calc = calculator;
init(calc);
mListener = calc.mListener;
setOnClickListener(mListener);
setOnLongClickListener(mListener);
}
Of course, this is because I know nothing of your custom Calculator class (i.e., whether it is even a sublcass of Context). This method will bypass the context casting completely, so you can pass whatever you like for your first argument for as long as it inherits from the Context class (most commonly an Activity).

2D Array grid on drawing canvas

I am writing an pixel art app that paints images the user draws on the screen to pixel look. There are two ways to approach it. Either pixelate the image after saving or have a grid before hand so the user draws the pixel image. I don't find anything on the later method. So my issue with the first is drawing a grid where if a cell is touched I would change the color of it. I tried drawing rectangles on a canvas but that was pointless because i couldn't control the cells.
I was thinking about nested for loops that creates a bitmap at each cell?
The following is just a simple, illustrative example. It is not optimized, implements no exception handling, etc.
public class PixelGridView extends View {
private int numColumns, numRows;
private int cellWidth, cellHeight;
private Paint blackPaint = new Paint();
private boolean[][] cellChecked;
public PixelGridView(Context context) {
this(context, null);
}
public PixelGridView(Context context, AttributeSet attrs) {
super(context, attrs);
blackPaint.setStyle(Paint.Style.FILL_AND_STROKE);
}
public void setNumColumns(int numColumns) {
this.numColumns = numColumns;
calculateDimensions();
}
public int getNumColumns() {
return numColumns;
}
public void setNumRows(int numRows) {
this.numRows = numRows;
calculateDimensions();
}
public int getNumRows() {
return numRows;
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
calculateDimensions();
}
private void calculateDimensions() {
if (numColumns < 1 || numRows < 1) {
return;
}
cellWidth = getWidth() / numColumns;
cellHeight = getHeight() / numRows;
cellChecked = new boolean[numColumns][numRows];
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
if (numColumns == 0 || numRows == 0) {
return;
}
int width = getWidth();
int height = getHeight();
for (int i = 0; i < numColumns; i++) {
for (int j = 0; j < numRows; j++) {
if (cellChecked[i][j]) {
canvas.drawRect(i * cellWidth, j * cellHeight,
(i + 1) * cellWidth, (j + 1) * cellHeight,
blackPaint);
}
}
}
for (int i = 1; i < numColumns; i++) {
canvas.drawLine(i * cellWidth, 0, i * cellWidth, height, blackPaint);
}
for (int i = 1; i < numRows; i++) {
canvas.drawLine(0, i * cellHeight, width, i * cellHeight, blackPaint);
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
int column = (int)(event.getX() / cellWidth);
int row = (int)(event.getY() / cellHeight);
cellChecked[column][row] = !cellChecked[column][row];
invalidate();
}
return true;
}
}
Here's a simple Activity for demonstration:
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
PixelGridView pixelGrid = new PixelGridView(this);
pixelGrid.setNumColumns(4);
pixelGrid.setNumRows(6);
setContentView(pixelGrid);
}
}
public class PixelGridView extends View {
//number of row and column
int horizontalGridCount = 2;
private Drawable horiz;
private Drawable vert;
private final float width;
public PixelGridView(#NonNull Context context) {
this(context, null);
}
public PixelGridView(#NonNull Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
horiz = new ColorDrawable(Color.WHITE); horiz.setAlpha(160);
vert = new ColorDrawable(Color.WHITE); vert.setAlpha(160);
width = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 0.9f, context.getResources().getDisplayMetrics());
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
horiz.setBounds(left, 0, right, (int) width);
vert.setBounds(0, top, (int) width, bottom);
}
private float getLinePosition(int lineNumber) {
int lineCount = horizontalGridCount;
return (1f / (lineCount + 1)) * (lineNumber + 1f);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// drawTask.start();
int count = horizontalGridCount;
for (int n = 0; n < count; n++) {
float pos = getLinePosition(n);
// Draw horizontal line
canvas.translate(0, pos * getHeight());
horiz.draw(canvas);
canvas.translate(0, - pos * getHeight());
// Draw vertical line
canvas.translate(pos * getWidth(), 0);
vert.draw(canvas);
canvas.translate(- pos * getWidth(), 0);
}
//drawTask.end(count);
}
}
and in your main activity:
//inside on create method
val myView = PixelGridView(this)
id_frame.addView(myView)
id_frame is frame layout in xml
This view class will draw grid of equidistance lines in Canvas based on how much GAP_WIDTH_DP is allocated
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Build;
import android.support.annotation.Nullable;
import android.support.annotation.RequiresApi;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.View;
public class PixelGridView extends View {
private int screenWidth;
private int screenHeight;
public static final int GAP_WIDTH_DP = 62;
private float GAP_WIDTH_PIXEL;
private Paint paint = new Paint();
public PixelGridView(Context context) {
super(context);
init(context);
}
public PixelGridView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
init(context);
}
public PixelGridView(Context context, #Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
#RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public PixelGridView(Context context, #Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
init(context);
}
public static float convertDpToPixel(float dp, Context context){
return dp * ((float) context.getResources().getDisplayMetrics().densityDpi / DisplayMetrics.DENSITY_DEFAULT);
}
public void init(Context context) {
// set paint color
paint.setColor(Color.GREEN);
// get view dimentions
getScreenDimensions();
}
private void getScreenDimensions() {
DisplayMetrics displayMetrics = new DisplayMetrics();
((Activity) getContext()).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
screenWidth = displayMetrics.widthPixels;
screenHeight = displayMetrics.heightPixels;
//gap size in pixel
GAP_WIDTH_PIXEL = convertDpToPixel(GAP_WIDTH_DP, getContext());
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
getScreenDimensions();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// draw Horizontal line from Y= 0 -> Y+=Gap... till screen width
float verticalPosition = 0;
while (verticalPosition <= screenHeight) {
canvas.drawLine(0, verticalPosition,
screenWidth, verticalPosition, paint);
verticalPosition += GAP_WIDTH_PIXEL;
}
// draw Vertical line from X=0 -> X+=Gap... till screen Height 0|||hor+gap|||W
float horizontalPosition = 0;
while (horizontalPosition <= screenWidth) {
canvas.drawLine(horizontalPosition, 0,
horizontalPosition, screenHeight,paint);
horizontalPosition += GAP_WIDTH_PIXEL;
}
}
}
One available option is to look into using the Android Gridview as the drawing grid; I have not tested this myself, however if you create an object to be touched in each cell with your desired pixel dimensions, you should be able to create a rudimentary Pixel Art application by saving the variables.
Note, grid view cells are sized based on their contents, as noted in How to set a cell size in Android grid view?
Also, when it comes to drawing things, there are many different ways to handle it, however following a guide or tutorial such as http://code.tutsplus.com/tutorials/android-sdk-create-a-drawing-app-touch-interaction--mobile-19202 is generally the best place to start and pull what you need from it.
Good luck!

Info about the Movie class for Android

I'm trying to show an animated gif. By the way I'm doing it with the class Movie. But the Android Developer page dont grant info about the methods.
How can I make the gif to be resized to fit the layout?
Thanks in advance
I've been trying to do the same thing (to display animated GIF) using this method.
It works only if you specify uses-sdk android:minSdkVersion="3"
For scaling ...
package com.example.GIFShow;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Movie;
import android.graphics.Rect;
import android.util.Log;
import android.view.View;
class MYGIFView extends View {
private static final boolean twigDebug = true;
private Movie mMovie;
private long mMovieStart;
MYGIFView(Context aContext, Movie aMovie) {
super(aContext);
if (aMovie == null)
return;
mMovie = aMovie;
mMovieStart = android.os.SystemClock.uptimeMillis();
}
protected void onDraw(Canvas aCanvas) {
super.onDraw(aCanvas);
if (mMovie == null || mMovie.duration() == 0)
return;
int relTime = (int)((android.os.SystemClock.uptimeMillis() - mMovieStart)
% mMovie.duration());
mMovie.setTime(relTime);
Bitmap movieBitmap = Bitmap.createBitmap(mMovie.width(), mMovie.height(),
Bitmap.Config.ARGB_8888);
Canvas movieCanvas = new Canvas(movieBitmap);
mMovie.draw(movieCanvas, 0, 0);
Rect src = new Rect(0, 0, mMovie.width(), mMovie.height());
Rect dst = new Rect(0, 0, this.getWidth(), this.getHeight());
aCanvas.drawBitmap(movieBitmap, src, dst, null);
this.invalidate();
}
}
Now you can get and pass a Movie object to the class in one of two ways ...
Get input GIF Movie object from project drawable folder
Movie movie = Movie.decodeStream
(context.getResources().openRawResource(R.drawable.somefile));
Or get input GIF Movie object from external storage
(/mnt/sdcard ... /mnt/extSdCard ... etc)
Movie movie = null;
try {
FileInputStream stream =
new FileInputStream(Environment.getExternalStorageDirectory() +
"/somefolder/somefile.gif");
try {
byte[] byteStream = streamToBytes(stream);
movie = Movie.decodeByteArray(byteStream, 0, byteStream.length);
}
finally {
stream.close();
}
}
catch (IOException e) { }
Now set the moving GIF image / Movie object into your activity view:
View view = new MYGIFView(this, movie);
setContentView(view);
If you get the GIF image / Movie object from external storage (second example) you'll need the supporting routine:
private byte[] streamToBytes(InputStream is) {
ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
byte[] buffer = new byte[1024];
int len;
try {
while ((len = is.read(buffer)) >= 0)
os.write(buffer, 0, len);
}
catch (java.io.IOException e) { }
return os.toByteArray();
}
You answer is good. It helped me alot.I have changed one thing for performance .Moved the bitmap creation to outside of ondraw
import java.io.InputStream;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Movie;
import android.graphics.Rect;
import android.os.SystemClock;
import android.util.AttributeSet;
import android.view.View;
public class GifView extends View {
private Movie mMovie;
InputStream mStream;
long mMoviestart;
private Context context;
public GifView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
this.context = context;
init();
}
public GifView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
init();
}
public GifView(Context context) {
super(context);
this.context = context;
init();
}
Bitmap movieBitmap = null;
private void init() {
InputStream object = this.getResources().openRawResource(
R.raw.postloadinganimation);
mMovie = Movie.decodeStream(object);// context.getResources().getAssets().open("PostLoadingAnimation.gif"));
movieBitmap = Bitmap.createBitmap(mMovie.width(),
mMovie.height(), Bitmap.Config.ARGB_8888);
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.TRANSPARENT);
super.onDraw(canvas);
final long now = SystemClock.uptimeMillis();
if (mMoviestart == 0) {
mMoviestart = now;
}
final int relTime = (int) ((now - mMoviestart) % mMovie.duration());
mMovie.setTime(relTime);
// mMovie.draw(canvas, 0, 0);
Canvas movieCanvas = new Canvas(movieBitmap);
mMovie.draw(movieCanvas, 0, 0);
Rect src = new Rect(0, 0, mMovie.width(), mMovie.height());
Rect dst = new Rect(0, 0, this.getWidth(), this.getHeight());
canvas.drawBitmap(movieBitmap, src, dst, null);
this.invalidate();
}
}
I know, this is very old post.
But you can try this ...
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (mMovie != null) {
int movieWidth = mMovie.width();
int movieHeight = mMovie.height();
/** Calculate horizontal scaling*/
float scaleH = 1f;
int measureModeWidth = MeasureSpec.getMode(widthMeasureSpec);
if (measureModeWidth != MeasureSpec.UNSPECIFIED) {
int maximumWidth = MeasureSpec.getSize(widthMeasureSpec);
if (movieWidth > maximumWidth) {
scaleH = (float) movieWidth / (float) maximumWidth;
}else{
scaleH = (float) maximumWidth / (float) movieWidth;
}
}
/** calculate vertical scaling*/
float scaleW = 1f;
int measureModeHeight = MeasureSpec.getMode(heightMeasureSpec);
if (measureModeHeight != MeasureSpec.UNSPECIFIED) {
int maximumHeight = MeasureSpec.getSize(heightMeasureSpec);
if (movieHeight > maximumHeight) {
scaleW = (float) movieHeight / (float) maximumHeight;
}else{
scaleW = (float) maximumHeight / (float) movieHeight;
}
}
/** calculate overall scale*/
mScale = Math.max(scaleH, scaleW);
mMeasuredMovieWidth = (int) (movieWidth * mScale);
mMeasuredMovieHeight = (int) (movieHeight * mScale);
setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
} else {
/*No movie set, just set minimum available size.*/
setMeasuredDimension(getSuggestedMinimumWidth(), getSuggestedMinimumHeight());
}
}
private void drawMovieFrame(Canvas canvas) {
mMovie.setTime(mCurrentAnimationTime);
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(mScale, mScale);
mLeft = (getWidth() - mMeasuredMovieWidth) / 2f;
mTop = (getHeight() - mMeasuredMovieHeight) / 2f;
mMovie.draw(canvas, mLeft / mScale, mTop / mScale);
canvas.restore();
}

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