Android Open Source - Divide_And_Conquer_Card_Shuffler Auto Resize Text View

• Back to App/card  ↑

From Project

Back to project page Divide_And_Conquer_Card_Shuffler.

License

The source code is released under:

MIT License

Java Source Code

package com.andrewkeeton.divide.and.conquer.card.shuffler;
//  w  w w  .j a v a2 s  .c om
import java.util.HashMap;

import android.content.Context;
import android.graphics.Rect;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;

/**
 * Text view that auto adjusts text size to fit within the view. If the text
 * size equals the minimum text size and still does not fit, append with an
 * ellipsis.
 * 
 * @author Chase Colburn
 * @since Apr 4, 2011
 */
public class AutoResizeTextView extends TextView {

  // Minimum text size for this text view
  public static final float MIN_TEXT_SIZE = 20;

  // Interface for resize notifications
  public interface OnTextResizeListener {
    public void onTextResize(TextView textView, float oldSize, float newSize);
  }
  
  private HashMap<String, Float> mTextSizeCache = new HashMap<String, Float>();

  // Registered resize listener
  private OnTextResizeListener mTextResizeListener;

  // Flag for text and/or size changes to force a resize
  private boolean mNeedsResize = false;

  // Text size that is set from code. This acts as a starting point for
  // resizing
  private float mTextSize;

  // Temporary upper bounds on the starting text size
  private float mMaxTextSize = 0;

  // Lower bounds for text size
  private float mMinTextSize = MIN_TEXT_SIZE;

  // Default constructor override
  public AutoResizeTextView(Context context) {
    this(context, null);
  }

  // Default constructor when inflating from XML file
  public AutoResizeTextView(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
  }

  // Default constructor override
  public AutoResizeTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    mTextSize = getTextSize();
  }

  /**
   * When text changes, set the force resize flag to true and reset the text
   * size.
   */
  @Override
  protected void onTextChanged(final CharSequence text, final int start,
      final int before, final int after) {
    //Log.w("AutoResizeTextView", "onTextChanged() called: \"" + text + "\"");
    
    mNeedsResize = true;
    resizeText(text);
    mNeedsResize = false;
  }

  /**
   * If the text view size changed, set the force resize flag to true
   */
  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    if (w != oldw || h != oldh) {
      mNeedsResize = true;
    }
  }

  /**
   * Register listener to receive resize notifications
   * 
   * @param listener
   */
  public void setOnResizeListener(OnTextResizeListener listener) {
    mTextResizeListener = listener;
  }

  /**
   * Override the set text size to update our internal reference values
   */
  @Override
  public void setTextSize(float size) {
    super.setTextSize(size);
    mTextSize = getTextSize();
  }

  /**
   * Override the set text size to update our internal reference values
   */
  @Override
  public void setTextSize(int unit, float size) {
    super.setTextSize(unit, size);
    mTextSize = getTextSize();
  }

  /**
   * Set the upper text size limit and invalidate the view
   * 
   * @param maxTextSize
   */
  public void setMaxTextSize(float maxTextSize) {
    mMaxTextSize = maxTextSize;
    requestLayout();
    invalidate();
  }

  /**
   * Return upper text size limit
   * 
   * @return
   */
  public float getMaxTextSize() {
    return mMaxTextSize;
  }

  /**
   * Set the lower text size limit and invalidate the view
   * 
   * @param minTextSize
   */
  public void setMinTextSize(float minTextSize) {
    mMinTextSize = minTextSize;
    requestLayout();
    invalidate();
  }

  /**
   * Return lower text size limit
   * 
   * @return
   */
  public float getMinTextSize() {
    return mMinTextSize;
  }

  /**
   * Reset the text to the original size
   */
  public void resetTextSize() {
    if (mTextSize > 0) {
      super.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
      mMaxTextSize = mTextSize;
    }
  }

  /**
   * Resize text after measuring
   */
  @Override
  protected void onLayout(boolean changed, int left, int top, int right,
      int bottom) {
    //Log.d("AutoResizeTextView", "onLayout() called");
    if (changed || mNeedsResize) {
      int widthLimit = (right - left) - getCompoundPaddingLeft()
          - getCompoundPaddingRight();
      int heightLimit = (bottom - top) - getCompoundPaddingBottom()
          - getCompoundPaddingTop();
      resizeText(this.getText(), widthLimit, heightLimit);
    }
    super.onLayout(changed, left, top, right, bottom);
  }

  /**
   * Resize the text size with default width and height
   */
  public void resizeText(CharSequence text) {
    int heightLimit = getHeight() - getPaddingBottom() - getPaddingTop();
    //Log.d("AutoResizeTextView", "heightLimit: " + heightLimit);
    int widthLimit = getWidth() - getPaddingLeft() - getPaddingRight();
    //Log.d("AutoResizeTextView", "widthLimit: " + widthLimit);
    resizeText(text, widthLimit, heightLimit);
  }

  /**
   * Resize the text size with specified width and height
   * 
   * @param width
   * @param height
   */
  public void resizeText(CharSequence text, int width, int height) {
    // Do not resize if the view does not have dimensions or there is no
    // text
    if (text == null || text.length() == 0 || height <= 0 || width <= 0
        || mTextSize == 0) {
      return;
    }
    
    float targetTextSize = mTextSize;
    TextPaint textPaint = getPaint();
    float oldTextSize = textPaint.getTextSize();
    
    // TODO: Encompass all stateful values in the cache lookup.
    if (mTextSizeCache.containsKey(text.toString())) {
      targetTextSize = mTextSizeCache.get(text.toString());
    } else {
      Rect bounds = new Rect();

      //Log.w("AutoResizeTextView", "Resizing text: \"" + this.getText() + "\"");

      /// Scale up
      while (true) {
        //Log.i("AutoResizeTextView", "targetTextSize: " + targetTextSize);

        getTextBounds(text, textPaint, targetTextSize, bounds);
        int textHeight = bounds.height();
        int textWidth = bounds.width();

        if (textHeight >= height || textWidth >= width) {
          break;
        }

        targetTextSize += 2.0f;
      }
      ///

      /// Scale down
      while (true) {
        //Log.i("AutoResizeTextView", "targetTextSize: " + targetTextSize);

        getTextBounds(text, textPaint, targetTextSize, bounds);
        int textHeight = bounds.height();
        int textWidth = bounds.width();

        if (textHeight <= height && textWidth <= width) {
          break;
        }

        targetTextSize -= 2.0f;
      }
      ///
    }
    
    mTextSizeCache.put(text.toString(), targetTextSize);
    
    // Leave some room for internal font padding.
    targetTextSize *= 0.85f;
    
    this.setTextSize(targetTextSize);

    // Notify the listener if registered
    if (mTextResizeListener != null) {
      mTextResizeListener.onTextResize(this, oldTextSize, targetTextSize);
    }

    // Reset force resize flag
    mNeedsResize = false;
  }
  
  private void getTextBounds(CharSequence text, TextPaint paint, float textSize, Rect bounds) {
    // Update the text paint object
    super.setTextSize(textSize);
    paint.getTextBounds(text.toString(), 0, text.length(), bounds);
    
    //Log.d("AutoResizeTextView", "textHeight: " + bounds.height());
    //Log.d("AutoResizeTextView", "textWidth: " + bounds.width());
  }
}

Java Source Code List

• Back to App/card  ↑