Draw a path progressively with getSegment - android

I created a custom view to draw a line, but progressively. I tried to use PathMeasure and getSegment, but the effect doesn't work. It just keeps drawing the line already with the final size.
private val paint = Paint().apply {
isAntiAlias = true
color = Color.WHITE
style = Paint.Style.STROKE
strokeWidth = 10f
}
override fun onDraw(canvas: Canvas?) {
super.onDraw(canvas)
val path = Path().apply {
moveTo(width/2.toFloat(), height/2.toFloat())
lineTo(width/2.toFloat(), height/4.toFloat())
}
val measure = PathMeasure(path, false)
val length = measure.length
val partialPath = Path()
measure.getSegment(0.0f, length, partialPath, true)
partialPath.rLineTo(0.0f, 0.0f)
canvas!!.drawPath(partialPath, paint)
}

you can do this with DashPathEffect
DashPathEffect dashPathEffect = new DashPathEffect(new float[]{1000.0f,9999999},0);
Paint.setPathEffect(dashPathEffect);
change 1000 to your length ("on" parts in Dash)
and set 99999999 to your max ("off" parts in Dash)
play with this parameters and read this article please

Here's how I made it, as #mohandes explained:
private var path = Path()
private var paint = Paint()
private val dashes = floatArrayOf(125f, 125f)
init {
paint = Paint().apply {
isAntiAlias = true
color = Color.WHITE
style = Paint.Style.STROKE
strokeWidth = 10.0f
pathEffect = CornerPathEffect(8f)
}
path = Path().apply {
moveTo(312f, 475f)
lineTo(312f, 375f)
}
val lineAnim = ValueAnimator.ofFloat(100f, 0f)
lineAnim.interpolator = LinearInterpolator()
lineAnim.addUpdateListener {
paint.pathEffect = ComposePathEffect(DashPathEffect(dashes, lineAnim.animatedValue as Float), CornerPathEffect(8f))
invalidate()
}
lineAnim.duration = 1000
lineAnim.start()
}
override fun onDraw(canvas: Canvas?) {
super.onDraw(canvas)
canvas!!.drawPath(path, paint)
}

Related

How to draw border on BottomNavigation MenuItem Icon?

I am developing an android app using:
Jetpack Lifecycle (ViewModel)
Jetpack Navigation
Coil (Image Loader)
I am trying to customize the BottomNavigationMenu.
But one thing is very hard...
The last tab is the User's profile Image with Border.
If the user's profile image background color is white, then the ui is weird.
So I should show the border.
class MainActivity {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
initBottomNav(binding.bottomNav)
vm.initProfileBottomIcon()
}
private fun initBottomNav(bottomNav: BottomNavigationView) {
val navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment
bottomNav.setupWithNavController(navHostFragment.navController)
bottomNav.itemIconTintList = null
vm.profileImgUrl.observe(this) { url ->
bottomNav.menu.findItem(R.id.profileFragment).load(this, url) {
transformations(CircleCropTransformation())
}
}
}
}
This code draws the profile image on the BottomNavigationMenu.
But not draw the border.
When I googling, there is no support for CircleCrop with Border on Coil (even Glide).
So I tried the below code, But it doesn't work well..
vm.profileImg.observe(this) { imgBitmap ->
val layerBorder = ResourcesCompat.getDrawable(resources, R.drawable.oval_trans_border1_red, null)
val layerIcon = BitmapDrawable(Resources.getSystem(), imgBitmap)
val layerDrawable = LayerDrawable(arrayOf(layerIcon, layerBorder))
val bottomNavProfile = bottomNav.menu.findItem(R.id.profileFragment)
val request = ImageRequest.Builder(this)
.data(layerDrawable)
.target {
bottomNavProfile.icon = it
}
.apply {
transformations(CircleCropTransformation())
}
.build()
imageLoader.enqueue(request)
}
Somebody help me please?
You can write your own Transformation with border like this:
class BorderedCircleCropTransformation(
private val borderSize: Float = 0f,
#ColorInt private val borderColor: Int = Color.BLUE
) : Transformation {
override fun key(): String = BorderedCircleCropTransformation::class.java.name
override suspend fun transform(pool: BitmapPool, input: Bitmap, size: Size): Bitmap {
val borderOffset = (borderSize * 2).toInt()
val halfWidth = input.width / 2
val halfHeight = input.height / 2
val circleRadius = Math.min(halfWidth, halfHeight).toFloat()
val newBitmap = Bitmap.createBitmap(
input.width + borderOffset,
input.height + borderOffset,
Bitmap.Config.ARGB_8888
)
// Center coordinates of the image
val centerX = halfWidth + borderSize
val centerY = halfHeight + borderSize
val paint = Paint()
val canvas = Canvas(newBitmap).apply {
// Set transparent initial area
drawARGB(0, 0, 0, 0)
}
// Draw the transparent initial area
paint.isAntiAlias = true
paint.style = Paint.Style.FILL
canvas.drawCircle(centerX, centerY, circleRadius, paint)
// Draw the image
paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN)
canvas.drawBitmap(input, borderSize, borderSize, paint)
// Draw the createBitmapWithBorder
paint.xfermode = null
paint.style = Paint.Style.STROKE
paint.color = borderColor
paint.strokeWidth = borderSize
canvas.drawCircle(centerX, centerY, circleRadius, paint)
return newBitmap
}
override fun equals(other: Any?) = other is BorderedCircleCropTransformation
override fun hashCode() = javaClass.hashCode()
override fun toString() = "BorderedCircleCropTransformation()"
private companion object {
val XFERMODE = PorterDuffXfermode(PorterDuff.Mode.SRC_IN)
}
}
internal val Bitmap.safeConfig: Bitmap.Config
get() = config ?: Bitmap.Config.ARGB_8888
then pass it as a transformation to coil and it will draw what you want.
I use this code for drawing border.

How to draw rounded corner polygons in Jetpack Compose Canvas?

I'm trying to create a rounded triangle using Canvas in Jetpack Compose.
I try this code for drawing triangle:
#Composable
fun RoundedTriangle() {
Canvas(modifier = Modifier.size(500.dp)) {
val trianglePath = Path().apply {
val height = size.height
val width = size.width
moveTo(width / 2.0f, 0f)
lineTo(width, height)
lineTo(0f, height)
}
drawPath(trianglePath, color = Color.Blue)
}
}
But I don't know how to round the triangle corners. I also tried to use arcTo, but I was unable to get a suitable result.
How can I draw something like the figure below?
For Stroke you can specify rounding like this:
drawPath(
...
style = Stroke(
width = 2.dp.toPx(),
pathEffect = PathEffect.cornerPathEffect(4.dp.toPx())
)
)
Yet Fill seems lack of support rounding. I've created a feature request, please star it.
But Canvas has drawOutline function, which accepts both Outline, which can wrap a Path, and Paint, for which you can specify pathEffect:
Canvas(modifier = Modifier.fillMaxWidth().aspectRatio(1f)) {
val rect = Rect(Offset.Zero, size)
val trianglePath = Path().apply {
moveTo(rect.topCenter)
lineTo(rect.bottomRight)
lineTo(rect.bottomLeft)
close()
}
drawIntoCanvas { canvas ->
canvas.drawOutline(
outline = Outline.Generic(trianglePath),
paint = Paint().apply {
color = Color.Black
pathEffect = PathEffect.cornerPathEffect(rect.maxDimension / 3)
}
)
}
}
Path helpers:
fun Path.moveTo(offset: Offset) = moveTo(offset.x, offset.y)
fun Path.lineTo(offset: Offset) = lineTo(offset.x, offset.y)
Result:
Based on #philip-dukhov answer, if anyone is interested in appliying this to a square
#Composable
fun SquirclePath(
modifier: Modifier,
smoothingFactor: Int = 60,
color: Color,
strokeWidth: Float,
) {
Canvas(
modifier = modifier
) {
val rect = Rect(Offset.Zero, size)
val percent = smoothingFactor.percentOf(rect.minDimension)
val squirclePath = Path().apply {
with(rect) {
lineTo(topRight)
lineTo(bottomRight)
lineTo(bottomLeft)
lineTo(topLeft)
// this is where the path is finally linked together
close()
}
}
drawIntoCanvas { canvas ->
canvas.drawOutline(
outline = Outline.Generic(squirclePath),
paint = Paint().apply {
this.color = color
this.style = PaintingStyle.Fill
this.strokeWidth = strokeWidth
pathEffect = PathEffect.cornerPathEffect(percent)
}
)
}
}
}
fun Int.percentOf(target:Float) = (this.toFloat() / 100) * target

How to draw a Button like rectangle with text in Android Canvas?

In Android app , I want to draw a button in canvas , like the image exactly the below image
I tried some stack overflow answers but can't get the exact output , particularly the light shadow below . My worst code is below
val corners = floatArrayOf(
80f, 80f, // Top left radius in px
80f, 80f, // Top right radius in px
0f, 0f, // Bottom right radius in px
0f, 0f // Bottom left radius in px
)
val path = Path()
val rect = RectF(550f, 500f, 100f, 300f)
paint.style = Paint.Style.FILL;
paint.color = Color.WHITE;
path.addRoundRect(rect, corners, Path.Direction.CW)
canvas?.drawPath(path, paint)
paint.style = Paint.Style.STROKE;
paint.color = Color.BLACK;
path.addRoundRect(rect, corners, Path.Direction.CW)
canvas?.drawPath(path, paint)
paint.setColor(Color.RED)
paint.setStyle(Paint.Style.FILL)
val paint2 = Paint()
paint2.setColor(Color.GREEN)
paint2.setTextSize(50f) //set text size
val w: Float = paint2.measureText("VIEW CAMPSITE MAP") / 2
val textSize: Float = paint2.textSize
canvas?.drawText("VIEW CAMPSITE MAP", 300f, 300f ,paint2);
Also I can't set text in correct position
I also need a gradient to show bulging state like a real material button
And also need an click listener in the canvas / paint
I need it in pure canvas and paint not in any views
please help me
Here is one of the ways. Dont forget to move all variables like text, textSize, etc in custom attributes. Also I didnt get what do you mean by "click listener in the canvas"
class CustomView #JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {
//constants. move them all to custom attributes
private val boxRadius = convertDpToPixel(10f)
private val boxColor = Color.parseColor("#52618e")
private val boxBackgroundColor = Color.WHITE
private val boxShadowSize = convertDpToPixel(2f)
private val boxStrokeWidth = convertDpToPixel(1f)
private val textColor = Color.parseColor("#21a207")
private val fontSize = convertDpToPixel(30f)
private val text = "View Campsite Plan"
private lateinit var boxShadow: RectF
private lateinit var boxBackground: RectF
private lateinit var boxShadowPaint: Paint
private lateinit var boxBackgroundPaint: Paint
private var textWidth = 0f
private var textSmallGlyphHeight = 0f
private lateinit var textPaint: Paint
override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
boxShadow = RectF(0f, 0f, w.toFloat(), h.toFloat())
boxBackground = RectF(boxStrokeWidth, boxStrokeWidth,
w.toFloat()-boxStrokeWidth, h.toFloat()-boxStrokeWidth-boxShadowSize)
boxShadowPaint = Paint().apply { color = boxColor }
boxBackgroundPaint = Paint().apply { color = boxBackgroundColor }
textPaint = Paint().apply {
color = textColor
textSize = fontSize
typeface = Typeface.create(Typeface.DEFAULT, Typeface.BOLD)
textWidth = measureText(text)
textSmallGlyphHeight = fontMetrics.run { ascent + descent }
}
}
override fun onDraw(canvas: Canvas?) {
canvas?.drawRoundRect(boxShadow, boxRadius, boxRadius, boxShadowPaint)
canvas?.drawRoundRect(boxBackground, boxRadius, boxRadius, boxBackgroundPaint)
val textStartPadding = (width - textWidth)/2f
val textTopPadding = (height - textSmallGlyphHeight)/2f
canvas?.drawText(text, textStartPadding, textTopPadding, textPaint)
}
private fun convertDpToPixel(dp: Float) =
dp*(resources.displayMetrics.densityDpi/DisplayMetrics.DENSITY_DEFAULT)
}

Draw transparent bitmap on backgound

I want to draw transparent bitmaps on a background in a game. However, the bitmap is not transparent, it still has white color in the background. Here is my code
inner class Canvass(context: Context) : View(context) {
override fun onDraw(canvas: Canvas) {
super.onDraw(canvas)
val frame_paint: Paint = Paint()
frame_paint.style = Paint.Style.FILL
frame_paint.isAntiAlias = true
val framegame = BitmapFactory.decodeResource (resources, R.drawable.frame)
canvas.drawBitmap (framegame, 0f, 0f, frame_paint)
canvas.drawPath(mPath, mPaint)
val tennis_paint: Paint = Paint()
tennis_paint.style = Paint.Style.FILL
tennis_paint.color = Color.TRANSPARENT
tennis_paint.isAntiAlias = true
val tennis = BitmapFactory.decodeResource (resources, R.drawable.tennis_ball)
canvas.drawBitmap (tennis, 50f, 200f, tennis_paint)
}
}
I found this code, it works for me.
val tennis_paint: Paint = Paint()
tennis_paint.style = Paint.Style.FILL
tennis_paint.isAntiAlias = true
val tennis = BitmapFactory.decodeResource (resources, R.drawable.tennis_ball)
var bitmap = transparent_bitmap(tennis)
canvas.drawBitmap (bitmap, 50f, 300f, tennis_paint)
fun transparent_bitmap(bmp:Bitmap):Bitmap{
var bitmap: Bitmap = Bitmap.createBitmap(
bmp.width,
bmp.height,
Bitmap.Config.ARGB_8888
)
bitmap.setHasAlpha(true)
for (x in 1..bmp.width-1){
for (y in 1..bmp.height-1){
var pixel = bmp.getPixel(x,y)
val redValue = Color.red(pixel)
val blueValue = Color.blue(pixel)
val greenValue = Color.green(pixel)
if ((redValue==255)and(blueValue==255)and(greenValue==255)){
bitmap.setPixel(x,y,Color.argb(1,0,0,0))
}else {
bitmap.setPixel(x,y,Color.rgb(redValue,greenValue,blueValue))
}
}
}
return bitmap
}

TextInputEditText - CompoundDrawable is not centered

Im trying to add a suffix to my TextInputEditText by creating a TextDrawable then setting that using compoundDrawable. Everything is going fairly well except the drawable gets clipped outside to right of the component. What could be causing this? So far ive tried changing the font size but that is not doing any difference... Is the drawable too wide or what?
The String is "kr/månad" and as you can see it is clipped..
XML
<android.support.design.widget.TextInputLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/text_input_layout"
style="#style/TextInputLayoutStyle"
android:theme="#style/TextInputLayoutTheme">
<android.support.design.widget.TextInputEditText
android:id="#+id/text_input_edit_text"
style="#style/TextInputEditTextStyle" />
</android.support.design.widget.TextInputLayout>
COMPONENT CODE
textInputEditText.setCompoundDrawables(null, null, TextDrawable(unitText), null)
TEXTDRAWABLE
class TextDrawable(private val text: String?) : Drawable() {
private val paint: Paint
init {
paint = Paint()
paint.color = Color.BLACK
paint.textSize = 44f
paint.isAntiAlias = true
paint.isFakeBoldText = true
paint.typeface = Typeface.create("sans-serif-light", Typeface.NORMAL)
paint.style = Paint.Style.FILL
paint.textAlign = Paint.Align.CENTER
}
override fun draw(canvas: Canvas) {
text?.let { text ->
canvas.drawText(text, 0f, 0f, paint)
}
}
override fun setAlpha(alpha: Int) {
paint.alpha = alpha
}
override fun setColorFilter(cf: ColorFilter?) {
paint.colorFilter = cf
}
override fun getOpacity(): Int {
return PixelFormat.TRANSLUCENT
}
}
Try this code:
class TextDrawable(private val text: String?) : Drawable() {
private val paint = Paint().apply {
color = Color.BLACK
textSize = 44f
isAntiAlias = true
isFakeBoldText = true
typeface = Typeface.create("sans-serif-light", Typeface.NORMAL)
style = Paint.Style.FILL
setBounds(0, 0, measureText(text).toInt(), 0)
}
override fun draw(canvas: Canvas) {
text?.let { text ->
canvas.drawText(text, 0f, 0f, paint)
}
}
override fun setAlpha(alpha: Int) {
paint.alpha = alpha
}
override fun setColorFilter(cf: ColorFilter?) {
paint.colorFilter = cf
}
override fun getOpacity(): Int {
return PixelFormat.TRANSLUCENT
}
}
The difference is in two lines. I removed this
paint.textAlign = Paint.Align.CENTER
and added this:
setBounds(0, 0, measureText(text).toInt(), 0)

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