Add Library content

TypeWriterView/src/main/java/com/nitish/typewriterview/TypeWriterView.java

@@ -1,4 +1,107 @@
 package com.nitish.typewriterview;
 
-public class TypeWriterView {
+import android.content.Context;
+import android.os.Handler;
+import android.util.AttributeSet;
+
+import androidx.appcompat.widget.AppCompatTextView;
+
+public class TypeWriterView extends AppCompatTextView {
+    private CharSequence mText;
+    private int mIndex;
+    private long mDelay = 40; //Default delay in ms
+    private Boolean isAnimationRunning = false;
+    private OnAnimationChangeListener mAnimationChangeListener;
+    private Boolean avoidTextOverflowAtEdge = true;
+
+    public TypeWriterView(Context context) {
+        super(context);
+    }
+
+    public TypeWriterView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    private Handler mHandler = new Handler();
+    private Runnable characterAdder = new Runnable() {
+        @Override
+        public void run() {
+            setText(mText.subSequence(0, mIndex++));
+            if(mIndex <= mText.length()) {
+                mHandler.postDelayed(characterAdder, mDelay);
+                isAnimationRunning = true;
+            }else {
+                isAnimationRunning = false;
+                if (mAnimationChangeListener != null) mAnimationChangeListener.onAnimationEnd();
+            }
+        }
+    };
+
+    public void animateText(CharSequence text) {
+        mText = generateText(text.toString());
+        mIndex = 0;
+
+        setText("");
+        mHandler.removeCallbacks(characterAdder);
+        mHandler.postDelayed(characterAdder, mDelay);
+    }
+
+    public void stopAnimation(){
+        if (isAnimationRunning) {
+            isAnimationRunning = false;
+            mHandler.removeCallbacks(characterAdder);
+            setText(mText);
+            if (mAnimationChangeListener != null) mAnimationChangeListener.onAnimationEnd();
+        }
+    }
+
+    public boolean isAnimationRunning(){
+        return isAnimationRunning;
+    }
+
+    public boolean isTextInitialised() {
+        return mText != null;
+    }
+
+    //To Explicitly Change the Delay
+    public void setCharacterDelay(long millis) {
+        mDelay = millis;
+    }
+
+    public String generateText(String mText){
+        if (avoidTextOverflowAtEdge){
+            return generateFormattedSequence(mText);
+        }
+        return mText;
+    }
+
+    public String generateFormattedSequence(String mText){
+        String[] words = mText.split(" ");
+        int viewWidth = getMeasuredWidth();
+        StringBuilder finalSequence = new StringBuilder();
+        for (String word : words){
+            String temp = finalSequence.substring(Math.max(finalSequence.lastIndexOf("\n"), 0)) + " " + word;
+            float textWidth = getPaint().measureText(temp);
+            if (textWidth >= viewWidth)
+                finalSequence.append("\n").append(word);
+            else if (finalSequence.length() <= 0)
+                finalSequence.append(word);
+            else
+                finalSequence.append(" ").append(word);
+        }
+        return finalSequence.toString();
+    }
+
+    //Explicitly turnoff "avoidTextOverflowAtEdge" to avoid weird text formatting in few cases (when view size is dynamic).
+    public void avoidTextOverflowAtEdge(boolean avoidTextOverflowAtEdge) {
+        this.avoidTextOverflowAtEdge = avoidTextOverflowAtEdge;
+    }
+
+    public interface OnAnimationChangeListener {
+        void onAnimationEnd();
+    }
+
+    public void setOnAnimationChangeListener(OnAnimationChangeListener onAnimationChangeListener) {
+        mAnimationChangeListener = onAnimationChangeListener;
+    }
 }