activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rl"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
tools:context=".MainActivity"
android:background="#b4aba7"
>
<ImageView
android:id="@+id/iv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<Button
android:id="@+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Draw Text"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
/>
</RelativeLayout>
MainActivity.java
package com.cfsuman.me.androidcode;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.EmbossMaskFilter;
import android.graphics.Paint;
import android.graphics.RadialGradient;
import android.graphics.Rect;
import android.graphics.Shader;
import android.graphics.Typeface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.graphics.Canvas;
import android.graphics.Bitmap;
import java.util.Random;
public class MainActivity extends AppCompatActivity {
private Context mContext;
private Resources mResources;
private RelativeLayout mRelativeLayout;
private Button mButton;
private ImageView mImageView;
private Random mRandom = new Random();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get the application context
mContext = getApplicationContext();
// Get the Resources
mResources = getResources();
// Get the widgets reference from XML layout
mRelativeLayout = (RelativeLayout) findViewById(R.id.rl);
mButton = (Button) findViewById(R.id.btn);
mImageView = (ImageView) findViewById(R.id.iv);
// Set a click listener for Button widget
mButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Initialize a new Bitmap
Bitmap bitmap = Bitmap.createBitmap(
600, // Width
300, // Height
Bitmap.Config.ARGB_8888 // Config
);
// Initialize a new Canvas instance
Canvas canvas = new Canvas(bitmap);
// Draw a solid color on the canvas as background
canvas.drawColor(Color.WHITE);
// Initialize a new Paint instance to draw the text
Paint paint = new Paint();
paint.setStyle(Paint.Style.FILL);
// Set the text color
paint.setColor(Color.RED);
paint.setAntiAlias(true);
/*
public void setTextSize (float textSize)
Set the paint's text size. This value must be > 0
Parameters
textSize : set the paint's text size.
*/
// Set the text size
paint.setTextSize(125);
/*
public void setTextAlign (Paint.Align align)
Set the paint's text alignment. This controls how the text is positioned
relative to its origin. LEFT align means that all of the text will be drawn
to the right of its origin (i.e. the origin specifieds the LEFT edge of
the text) and so on.
Parameters
align : set the paint's Align value for drawing text.
*/
/*
Paint.Align
Align specifies how drawText aligns its text relative to
the [x,y] coordinates. The default is LEFT.
CENTER : The text is drawn centered horizontally on the x,y origin
LEFT : The text is drawn to the right of the x,y origin
RIGHT : The text is drawn to the left of the x,y origin
*/
// Text alignment
paint.setTextAlign(Paint.Align.CENTER);
/*
Typeface
The Typeface class specifies the typeface and intrinsic style of a font.
This is used in the paint, along with optionally Paint settings like
textSize, textSkewX, textScaleX to specify how text appears when
drawn (and measured).
*/
/*
public static Typeface create (Typeface family, int style)
Create a typeface object that best matches the specified existing typeface
and the specified Style. Use this call if you want to pick a new style from
the same family of an existing typeface object. If family is null,
this selects from the default font's family.
Parameters
family : May be null. The name of the existing type face.
style : The style (normal, bold, italic) of the typeface.
e.g. NORMAL, BOLD, ITALIC, BOLD_ITALIC
Returns
The best matching typeface.
*/
// Initialize a typeface object to draw text on canvas
Typeface typeface = Typeface.create(Typeface.SANS_SERIF,Typeface.BOLD_ITALIC);
// Set the paint font
paint.setTypeface(typeface);
// Initialize a new EmbossMaskFilter instance
EmbossMaskFilter filter = new EmbossMaskFilter(
new float[]{1,5,1}, // direction of the light source
0.5f, // ambient light between 0 to 1
10, // specular highlights
7.5f // blur before applying lighting
);
// Apply the MaskFilter to draw embossed text
paint.setMaskFilter(filter);
// Define the text to draw on canvas
String txt = "ANDROID";
/*
public void drawText (String text, float x, float y, Paint paint)
Draw the text, with origin at (x,y), using the specified paint. The origin
is interpreted based on the Align setting in the paint.
Parameters
text : The text to be drawn
x : The x-coordinate of the origin of the text being drawn
y : The y-coordinate of the baseline of the text being drawn
paint : The paint used for the text (e.g. color, size, style)
*/
// calculate the y position of canvas to draw the text
Rect rectangle = new Rect();
/*
public void getTextBounds (String text, int start, int end, Rect bounds)
Return in bounds (allocated by the caller) the smallest rectangle that
encloses all of the characters, with an implied origin at (0,0).
Parameters
text : String to measure and return its bounds
start : Index of the first char in the string to measure
end : 1 past the last char in the string measure
bounds : Returns the unioned bounds of all the text. Must be allocated by
the caller.
*/
paint.getTextBounds(
txt, // text
0, // start
txt.length(), // end
rectangle // bounds
);
// Initialize a new RadialGradient object
RadialGradient gradient = new RadialGradient(
mRandom.nextInt(rectangle.right),
mRandom.nextInt(rectangle.bottom),
mRandom.nextInt(rectangle.right),
new int[]{
getRandomHSVColor(),
getRandomHSVColor(),
getRandomHSVColor(),
getRandomHSVColor(),
getRandomHSVColor()
},
null, // Stops position is undefined
Shader.TileMode.MIRROR // Shader tiling mode
);
// Apply the RadialGradient as paint shader
paint.setShader(gradient);
//Finally, Draw the text on the canvas at the horizontal and vertical center position
canvas.drawText(
txt, // Text to draw
canvas.getWidth()/2, // x
canvas.getHeight()/2 + Math.abs(rectangle.height())/2, // y
paint // Paint
);
// Display the newly created bitmap on app interface
mImageView.setImageBitmap(bitmap);
}
});
}
// Custom method to generate random HSV color
protected int getRandomHSVColor(){
// Generate a random hue value between 0 to 360
int hue = mRandom.nextInt(361);
// We make the color depth full
float saturation = 1.0f;
// We make a full bright color
float value = 1.0f;
// We avoid color transparency
int alpha = 255;
// Finally, generate the color
int color = Color.HSVToColor(alpha,new float[]{hue,saturation,value});
// Return the color
return color;
}
}
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- How to use BlurMaskFilter
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- How to use TabLayout
- How to send and receive Broadcast
