I have been trying to make a photo sharing app, with the ability to add your image and name to the image. I have been messing with Canvas for the whole day, but couldn't get good results. I was able to draw the name and bitmap, but they didn't look so good.
That's why I am here asking about is there any library or piece of code that could help me in making something similar to [this][1]. I wasn't able to find any thing for it.
EDIT: Sorry for not adding my own code
Here is my code from my latest try
public void AddText(Position2D pos){
//Position2D is an enum having the 4 corners of the image
bmWorking= bmOriginal.copy(Bitmap.Config.ARGB_8888,true);
Canvas canvas = new Canvas(bmWorking);
Paint paint = new Paint();
paint.setColor(Color.WHITE);
paint.setStyle(Paint.Style.FILL);
Paint textPaint = new Paint();
textPaint.setColor(Color.BLACK);
float width = (35f/100f) * bmWorking.getWidth();
float height = (width/16f) * 3;
textPaint.setTextSize(height - 4); //I wanted to have some space (margin) above and below the text
textPaint.setTextAlign(Paint.Align.LEFT);
float [] coords = getPositionCoords(pos, width, height); //getPositionCoords returns a float array with the Left,Top,Right,Bottom position calculated based on the width and height
canvas.drawRect(coords[0],coords[1], coords[2], coords[3],paint);
username = "Haider Ali Punjabi";
canvas.drawText(username, coords[0] ,coords[3], textPaint);
bitmapView.setImageBitmap(bmWorking);
}
Here is the result
UPDATE:
#pskink gave me this code
which works nicely
if you want to customize it, then instead of solid white rectangle (like in your original code) use a Drawable and the result could be something like this:
the code:
// for int gravity: see android.view.Gravity, like Gravity.LEFT, Gravity.BOTTOM, etc
// for example:
// Bitmap out = addText(this, in, "Haider Ali Punjabi", android.R.drawable.alert_light_frame, Gravity.BOTTOM, new Point(10, 10));
public Bitmap addText(Context ctx, Bitmap in, String text, int resId, int gravity, Point pad) {
if (pad == null) pad = new Point();
Bitmap out = in.copy(Bitmap.Config.ARGB_8888, true);
Canvas canvas = new Canvas(out);
Paint textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
textPaint.setColor(Color.BLACK);
textPaint.setTextAlign(Paint.Align.LEFT);
// textPaint.setTextSize(128);
Rect inBounds = new Rect();
textPaint.getTextBounds(text, 0, text.length(), inBounds);
float scale = out.getWidth() * 0.35f / inBounds.width();
Rect container = new Rect(0, 0, out.getWidth(), out.getHeight());
Rect outBounds = new Rect();
int w = (int) (inBounds.width() * scale);
int h = (int) (inBounds.height() * scale);
Gravity.apply(gravity, 2 * pad.x + w, 2 * pad.y + h, container, outBounds);
Drawable dr = ctx.getResources().getDrawable(resId);
Rect padding = new Rect();
dr.getPadding(padding);
dr.setBounds(outBounds.left - padding.left, outBounds.top - padding.top, outBounds.right + padding.right, outBounds.bottom + padding.bottom);
dr.draw(canvas);
Matrix matrix = new Matrix();
RectF src = new RectF(inBounds);
RectF dst = new RectF(outBounds);
dst.inset(pad.x, pad.y);
matrix.setRectToRect(src, dst, Matrix.ScaleToFit.CENTER);
canvas.concat(matrix);
canvas.drawText(text, 0, 0, textPaint);
return out;
}
I'm overriding View on Android to do some custom drawing, but the rendered view has not very good quality, especially the text. I have found a couple of solutions, but none worked for me. Attaching the code here. Thank you for any help.
#Override
protected void onDraw(Canvas canvas) {
int width = canvas.getWidth();
int height = canvas.getHeight();
Point a = new Point(0, 0);
Point b = new Point(width / 2, height);
Point c = new Point(width, 0);
Path trianglePath = new Path();
trianglePath.moveTo(a.x, a.y);
trianglePath.lineTo(b.x, b.y);
trianglePath.lineTo(c.x, c.y);
trianglePath.lineTo(a.x, a.y);
Paint paint = new Paint();
paint.setStrokeWidth(1);
paint.setColor(Color.parseColor("#7A7A7A"));
paint.setStyle(Paint.Style.STROKE);
paint.setAntiAlias(true);
canvas.drawPath(trianglePath, paint);
Paint textPaint = new Paint();
textPaint.setStyle(Paint.Style.FILL);
textPaint.setColor(Color.WHITE);
textPaint.setTextSize(height / 6);
textPaint.setTypeface(TypefaceUtils.getTypeface(getContext(), TypefaceUtils.AVAILABLE_FONTS.ROBOTO_THIN));
String receive = getContext().getString(R.string.receive_password).split("\n")[0];
String password = getContext().getString(R.string.receive_password).split("\n")[1];
Rect receiveBounds = new Rect();
Rect passwordBounds = new Rect();
textPaint.getTextBounds(receive, 0, receive.length(), receiveBounds);
textPaint.getTextBounds(password, 0, password.length(), passwordBounds);
canvas.drawText(
receive,
(width - receiveBounds.width()) / 2,
height / 3 - receiveBounds.height() + receiveBounds.height() / 5,
textPaint);
canvas.drawText(
password,
(width - passwordBounds.width()) / 2,
height / 3 + receiveBounds.height(),
textPaint);
canvas.scale(1, 1);
}
Try setting textpaint.setAntiAlias(true);
EDIT: The problem came from the emulator, the error did not appear on a real device :(
I'm trying to draw some text in a custom view and must there for measure it but the value of the Paint.getTextBounds() returns a height which is about 30% higher then the actual text which gives everything a quirky look.
I found this: Android Paint: .measureText() vs .getTextBounds() and tried to add the solution code to my own onDraw and saw that i the same measuring error as in my code. Here is a picture of the result:
Compare with:
The image is copied from Android Paint: .measureText() vs .getTextBounds()
Note the spacing above the text in the first picture. Any Ideas what might be causing this? Or are there alternative ways to measure height of a drawn string?
Here is the onDraw method:
#Override
public void onDraw(Canvas canvas){
// canvas.drawColor(color_Z1);
// r.set(0, 0, (int)(width*progress), height);
// paint.setColor(color_Z2);
//// canvas.drawRect(r, paint);
// textPaint.getTextBounds(text, 0, text.length(), r);
// canvas.drawRect(r, paint);
// canvas.drawText(text, 0, r.height(), textPaint);
final String s = "Hello. I'm some text!";
Paint p = new Paint();
Rect bounds = new Rect();
p.setTextSize(60);
p.getTextBounds(s, 0, s.length(), bounds);
float mt = p.measureText(s);
int bw = bounds.width();
Log.i("LCG", String.format(
"measureText %f, getTextBounds %d (%s)",
mt,
bw, bounds.toShortString())
);
bounds.offset(0, -bounds.top);
p.setStyle(Style.STROKE);
canvas.drawColor(0xff000080);
p.setColor(0xffff0000);
canvas.drawRect(bounds, p);
p.setColor(0xff00ff00);
canvas.drawText(s, 0, bounds.bottom, p);
}
i didnot test your code but i dont see any problems with Paint.getTextBounds():
public class TextBoundsTest extends View {
private Paint paint;
private Rect bounds;
public TextBoundsTest(Context context) {
super(context);
paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setTextSize(32);
bounds = new Rect();
}
#Override
protected void onDraw(Canvas canvas) {
String text = "this is my text";
paint.getTextBounds(text, 0, text.length(), bounds);
Log.d(TAG, "onDraw " + bounds);
int x = (getWidth() - bounds.width()) / 2;
int y = 70;
paint.setColor(0xff008800);
bounds.offset(x, y);
canvas.drawRect(bounds, paint);
paint.setColor(0xffeeeeee);
canvas.drawText(text, x, y, paint);
}
}
add this in Activity.onCreate:
TextBoundsTest view = new TextBoundsTest(this);
setContentView(view);
the result is:
How to draw a filled rectangle with specified bounds and inside that rectangle text to be drawn using Canvas Android ?? I tried
mPaint.setColor(Color.GREEN);
canvas.drawText(mText, x, y, mPaint);
mPaint.setColor(Color.BLACK);
canvas.drawRect(x, y, x + w, y + h, mPaint);
but text is not inside of that rectangle. Can any buddy tell me how to draw a rectangle surrounding specified text with consideration of text size ??
Here i have hardcoded x and y values. You can change them
mpaint= new Paint();
mpaint.setColor(Color.RED);
mpaint.setStyle(Style.FILL);
paint2= new Paint();
paint2.setColor(Color.GREEN);
paint2.setTextSize(50); //set text size
float w = paint2.measureText(s)/2;
float textSize = paint2.getTextSize();
#Override
protected void onDraw(Canvas canvas) {
paint2.setTextAlign(Paint.Align.CENTER);
canvas.drawRect(300-w, 300 - textsize, 300 + w, 300, mpaint);
canvas.drawText(s, 300, 300 ,paint2); //x=300,y=300
}
Edit :
Its bad a idea to call measureText in onDraw. You can do that outside of onDraw.
There is a video on also about performance and why you should avoid allocations in onDraw. https://www.youtube.com/watch?v=HAK5acHQ53E
Resulting snap shot
If you have to center the text inside de rect you have use this code
mpaint= new Paint();
mpaint.setColor(Color.RED);
mpaint.setStyle(Style.FILL);
paint2= new Paint();
paint2.setColor(Color.GREEN);
paint2.setTextSize(50); //set text size
float w = paint2.measureText(s)/2;
float textSize = paint2.getTextSize();
#Override
protected void onDraw(Canvas canvas) {
paint2.setTextAlign(Paint.Align.CENTER);
Rect rect = new Rect(300-w, 300 - textsize, 300 + w, 300);
canvas.drawRect(rect, mpaint);
canvas.drawText(s, rect.centerX(), rect.centerY() ,paint2); // center text inside rect
}
This might be very late for this particular query but I think many will find this answer useful. So, the problem with the Canvas for any CustomView is that, you can get the width for a particular text, but it's not that easy to get the height of the text. Also if you are using canvas.drawText(....) with simple Paint object, you can not draw multi line text. So, use the below code within your onDraw() method.
String displayText = "Hello World";
int mainTextPositionX = getWidth() / 2 ;
int mainTextPositionY = getHeight() / 2;
StaticLayout textStaticLayout;
TextPaint textPaint;
textPaint = new TextPaint();
textPaint.setTextAlign(Paint.Align.CENTER);
textPaint.setColor(Color.BLUE);
textPaint.setAntiAlias(true);
textPaint.setTextSize(convertDpToPixel(30, context));
textPaint.setTextAlign(Paint.Align.CENTER);
highlightedRectPaint = new Paint();
highlightedRectPaint.setStrokeWidth(12);
highlightedRectPaint.setStyle(Paint.Style.STROKE);
highlightedRectPaint.setColor(Color.RED);
highlightedRectPaint.setAntiAlias(true);
if(android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
textStaticLayout = StaticLayout
.Builder
.obtain(displayText, 0, displayText.length(), textPaint, (int) textPaint.measureText(displayText))
.build();
}else{
textStaticLayout = new StaticLayout(
displayText, textPaint, (int)textPaint.measureText(displayText), Layout.Alignment.ALIGN_CENTER, 1.0f, 0.0f, false);
}
Rect highlightedTextBorderRect = new Rect();
highlightedTextBorderRect.top = mainTextPositionY-20;
highlightedTextBorderRect.left = mainTextPositionX-
((int)textPaint.measureText(displayText)/2)-20;
highlightedTextBorderRect.right = mainTextPositionX+
((int)textPaint.measureText(displayText)/2) + 20;
highlightedTextBorderRect.bottom = mainTextPositionY+
(int)textStaticLayout.getHeight()+20;
canvas.save();
canvas.translate(mainTextPositionX, mainTextPositionY);
textStaticLayout.draw(canvas);
canvas.restore();
canvas.drawRect(highlightedTextBorderRect,highlightedRectPaint);
just make sure that, you declare all the objects and variable outside of the draw() method. And this will draw a rectangle outline around the text with multi line support. If you want the rectangle to have a fill, then just use the highlightedRectPaint and change the setStyle(Paint.Style.FILL). Hope that helps.
I have two points in the canvas, now I'm able to draw a line between those points like this below image by using
This code canvas.drawLine(p1.x, p1.y, p2.x, p2.y, paint);
I want to draw the arc between two points like below image.
How can I draw like this.
Finally I got the solution from this code:
float radius = 20;
final RectF oval = new RectF();
oval.set(point1.x - radius, point1.y - radius, point1.x + radius, point1.y+ radius);
Path myPath = new Path();
myPath.arcTo(oval, startAngle, -(float) sweepAngle, true);
To calculate startAngle, use this code:
int startAngle = (int) (180 / Math.PI * Math.atan2(point.y - point1.y, point.x - point1.x));
Here, point1 means where you want to start drawing the Arc. sweepAngle means the angle between two lines. We have to calculate that by using two points like the blue points in my Question image.
Do something like this:
//Initialized paint on a class level object.
Paint p = new Paint();
p.setColor(Color.BLACK);
//Calculate the rect / bounds of oval
RectF rectF = new RectF(50, 20, 100, 80);
#Override
protected void onDraw(Canvas canvas) {
//Do the drawing in onDraw() method of View.
canvas.drawArc (rectF, 90, 45, false, p);
}
first we need to visual how the coordinates are in terms of start and sweep angels then it will become more clear.
so if you wanted just the right top piece of the circle, we could do something like this:
val rect = RectF(0f, 0f, 500f, 300f)
val paint = Paint()
paint.apply {
strokeWidth = 5f
setStyle(Paint.Style.STROKE)
color = COLOR.BLUE
}
path.addArc(rect, 270f, 90f)
..
this starts at 270 (per the diagram above and 'sweeps` 90 degrees forward. you then have this shape:
let's create one more so you get the hang of it. this time let's use a negative value: we want to create a semi half moon (arc) starting from the right side:
path.addArc(rect, 0f, -180f)
here we started at 0 and 'sweeped` -180 degrees.
and the results are:
I was trying to do something a little different and it's all about calculating sweep and start angles.
I wanted to show an arc that represents progress on a circle that goes from top to bottom.
So I had progress value from 0...100 and I want to show an arc that start from top to bottom to fill the circle when the progress is 100.
To calculate the sweepAngle I use:
int sweepAngle = (int) (360 * (getProgress() / 100.f));
Next is to calculate the startAngle
int startAngle = 270 - sweepAngle / 2;
Start Angle is calculated this way because:
It's always going to start from the left side, starting from the top to bottom. So starting angle at the top equals 270 (Note that it goes clockwise and 0 = 3 o'clock, so 12 o'clock equals 270 degrees)
Next I want to calculate how far I'm going to get away from my starting point (270) and to do that I only calculate half of the sweep angle because only half of the arc will be on the left side and the other half on the right side.
So considering I have progress of 25%
sweepAngle = 90 degrees (90 degrees is quarter of a circle)
start angle = 225 (45 degrees away from 270)
If you want the progress to go from other sides (Left to right, right to left etc..) you will only need to replace 270 with the starting the angle.
I may be late to answer but I got more information.
After Android Lollipop there are two ways to address this problem
public void drawArc(RectF oval, float startAngle, float sweepAngle,
boolean useCenter, Paint paint)
public void drawArc(float left, float top, float right, float bottom,
float startAngle, float sweepAngle, boolean useCenter, Paint paint)
Usage:
RectF rectF = new RectF(left, top, right, bottom);
// method 1
canvas.drawArc (rectF, 90, 45, true, paints[0]);
// method 2
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
canvas.drawArc (left, top, right, bottom, 0, 45, true, paints[1]);
}
Sweep angle is nothing more than angle of Sector which is drawn clockwise eg. for below code
private void drawArcs(Canvas canvas) {
RectF rectF = new RectF(left, top, right, bottom);
// white arc
canvas.drawArc (rectF, 90, 45, true, paints[0]);
// Green arc
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
canvas.drawArc (left, top, right, bottom, 0, 45, true, paints[1]);
}
// Red stroked arc
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
canvas.drawArc (left, top, right, bottom, 180, 45, true, paints[2]);
}
}
Result will look like this
Same can be achieved with the help of defining Paths and then iterating over them in onDraw method as illustrated in this snippet:
public class ArcDrawable extends Drawable {
private int left, right, top, bottom;
private Paint[] paints = new Paint[3];
private HashMap<Path, Paint> pathMap = new HashMap();
public ArcDrawable() {
// white paint
Paint whitePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
whitePaint.setColor(Color.WHITE);
paints[0]= whitePaint;
// green paint
Paint greenPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
greenPaint.setColor(Color.GREEN);
paints[1]= greenPaint;
// red paint
Paint redPaint =new Paint(Paint.ANTI_ALIAS_FLAG);
redPaint.setColor(Color.RED);
redPaint.setStyle(Paint.Style.STROKE);
paints[2]= redPaint;
}
#Override
public void draw(Canvas canvas) {
//----------USE PATHS----------
// Define and use custom Path
for (Map.Entry<Path, Paint> entry : pathMap.entrySet()) {
// Draw Path on respective Paint style
canvas.drawPath(entry.getKey(), entry.getValue());
}
// -------OR use conventional Style---------
//drawArcs(canvas);
}
//Same result
private void drawArcs(Canvas canvas) {
RectF rectF = new RectF(left, top, right, bottom);
// method 1
canvas.drawArc (rectF, 90, 45, true, paints[0]);
// method 2
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
canvas.drawArc (left, top, right, bottom, 0, 45, true, paints[1]);
}
// method two with stroke
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
canvas.drawArc (left, top, right, bottom, 180, 45, true, paints[2]);
}
}
#Override
protected void onBoundsChange(Rect bounds) {
super.onBoundsChange(bounds);
int width = bounds.width();
int height = bounds.height();
left = bounds.left;
right = bounds.right;
top = bounds.top;
bottom = bounds.bottom;
final int size = Math.min(width, height);
final int centerX = bounds.left + (width / 2);
final int centerY = bounds.top + (height / 2);
pathMap.clear();
//update pathmap using new bounds
recreatePathMap(size, centerX, centerY);
invalidateSelf();
}
private Path recreatePathMap(int size, int centerX, int centerY) {
RectF rectF = new RectF(left, top, right, bottom);
// first arc
Path arcPath = new Path();
arcPath.moveTo(centerX,centerY);
arcPath.arcTo (rectF, 90, 45);
arcPath.close();
// add to draw Map
pathMap.put(arcPath, paints[0]);
//second arc
arcPath = new Path();
arcPath.moveTo(centerX,centerY);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
arcPath.arcTo (rectF, 0, 45);
}
arcPath.close();
// add to draw Map
pathMap.put(arcPath, paints[1]);
// third arc
arcPath = new Path();
arcPath.moveTo(centerX,centerY);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
arcPath.arcTo (rectF, 180, 45);
}
arcPath.close();
// add to draw Map
pathMap.put(arcPath, paints[2]);
return arcPath;
}
#Override
public void setAlpha(int alpha) {
}
#Override
public void setColorFilter(#Nullable ColorFilter colorFilter) {
}
#Override
public int getOpacity() {
return 0;
}
}
Complete source code:
https://github.com/hiteshsahu/Arc-Drawable
a sample for draw arc.
public static Bitmap clipRoundedCorner(Bitmap bitmap, float r, boolean tr, boolean tl, boolean bl, boolean br)
{
int W = bitmap.getWidth();
int H = bitmap.getHeight();
if (r < 0)
r = 0;
int smallLeg = W;
if(H < W )
smallLeg = H;
if (r > smallLeg)
r = smallLeg / 2;
float lineStop = r/2;
Path path = new Path();
path.moveTo(0,0);
if(tr)
{
path.moveTo(0, lineStop);
path.arcTo(new RectF(0,0, r,r), 180, 90, false);
}
path.lineTo(W-lineStop, 0);
if(tl)
path.arcTo(new RectF(W-r,0, W,r), 270, 90, false);
else
path.lineTo(W, 0);
path.lineTo(W, H-lineStop);
if(bl)
path.arcTo(new RectF(W-r,H-r, W,H), 0, 90, false);
else
path.lineTo(W, H);
path.lineTo(lineStop, H);
if(br)
path.arcTo(new RectF(0,H-r, r,H), 90, 90, false);
else
path.lineTo(0,H);
if(tr)
path.lineTo(0,lineStop);
else
path.lineTo(0,0);
Bitmap output = Bitmap.createBitmap(W, H, Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(Color.BLACK);
canvas.drawPath(path, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, 0, 0, paint);
return output;
}
A simple solution was suggested here by Langkiller. This draws a cubic line from the start point via the control point to the end point.
Path path = new Path();
float startX = 0;
float startY = 2;
float controlX = 2;
float controlY = 4;
float endX = 4
float endY = 2
conePath.cubicTo(startX, startY, controlX, controlY,endX, endY);
Paint paint = new Paint();
paint.setARGB(200, 62, 90, 177);
paint.setStyle(Paint.Style.FILL);
canvas.drawPath(path, paint)