src/com/android/calculator2/CalculatorText.java - platform/packages/apps/ExactCalculator - Git at Google

 /*
  * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.calculator2;

 import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.Rect;
 import android.text.Layout;
 import android.text.TextPaint;
 import android.text.method.ScrollingMovementMethod;
 import android.util.AttributeSet;
 import android.util.TypedValue;
 import android.view.ActionMode;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.TextView;

 /**
  * TextView adapted for Calculator display.
  */
 public class CalculatorText extends AlignedTextView implements View.OnLongClickListener {

     private final ActionMode.Callback2 mPasteActionModeCallback = new ActionMode.Callback2() {

         @Override
         public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
             if (item.getItemId() == R.id.menu_paste) {
                 paste();
                 mode.finish();
                 return true;
             }
             return false;
         }

         @Override
         public boolean onCreateActionMode(ActionMode mode, Menu menu) {
             final ClipboardManager clipboard = (ClipboardManager) getContext()
                     .getSystemService(Context.CLIPBOARD_SERVICE);
             if (clipboard.hasPrimaryClip()) {
                 bringPointIntoView(length());
                 MenuInflater inflater = mode.getMenuInflater();
                 inflater.inflate(R.menu.paste, menu);
                 return true;
             }
             // Prevents the selection action mode on double tap.
             return false;
         }

         @Override
         public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
             return false;
         }

         @Override
         public void onDestroyActionMode(ActionMode mode) {
             mActionMode = null;
         }

         @Override
         public void onGetContentRect(ActionMode mode, View view, Rect outRect) {
             super.onGetContentRect(mode, view, outRect);
             outRect.top += getTotalPaddingTop();
             outRect.right -= getTotalPaddingRight();
             outRect.bottom -= getTotalPaddingBottom();
             // Encourage menu positioning towards the right, possibly over formula.
             outRect.left = outRect.right;
         }
     };

     // Temporary paint for use in layout methods.
     private final TextPaint mTempPaint = new TextPaint();

     private final float mMaximumTextSize;
     private final float mMinimumTextSize;
     private final float mStepTextSize;

     private int mWidthConstraint = -1;

     private ActionMode mActionMode;

     private OnPasteListener mOnPasteListener;
     private OnTextSizeChangeListener mOnTextSizeChangeListener;

     public CalculatorText(Context context) {
         this(context, null /* attrs */);
     }

     public CalculatorText(Context context, AttributeSet attrs) {
         this(context, attrs, 0 /* defStyleAttr */);
     }

     public CalculatorText(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);

         final TypedArray a = context.obtainStyledAttributes(
                 attrs, R.styleable.CalculatorText, defStyleAttr, 0);
         mMaximumTextSize = a.getDimension(
                 R.styleable.CalculatorText_maxTextSize, getTextSize());
         mMinimumTextSize = a.getDimension(
                 R.styleable.CalculatorText_minTextSize, getTextSize());
         mStepTextSize = a.getDimension(R.styleable.CalculatorText_stepTextSize,
                 (mMaximumTextSize - mMinimumTextSize) / 3);
         a.recycle();

         // Allow scrolling by default.
         setMovementMethod(ScrollingMovementMethod.getInstance());

         // Reset the clickable flag, which is added when specifying a movement method.
         setClickable(false);

         // Add a long click to start the ActionMode manually.
         setOnLongClickListener(this);
     }

     @Override
     public boolean onLongClick(View v) {
         mActionMode = startActionMode(mPasteActionModeCallback, ActionMode.TYPE_FLOATING);
         return true;
     }

     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         // Re-calculate our textSize based on new width.
         final int width = MeasureSpec.getSize(widthMeasureSpec)
                 - getPaddingLeft() - getPaddingRight();
         if (mWidthConstraint != width) {
             mWidthConstraint = width;

             if (!isLaidOut()) {
                 // Prevent shrinking/resizing with our variable textSize.
                 setTextSizeInternal(TypedValue.COMPLEX_UNIT_PX, mMaximumTextSize,
                         false /* notifyListener */);
                 setMinHeight(getLineHeight() + getCompoundPaddingBottom()
                         + getCompoundPaddingTop());
             }

             setTextSizeInternal(TypedValue.COMPLEX_UNIT_PX, getVariableTextSize(getText()),
                     false);
         }

         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
     }

     public int getWidthConstraint() { return mWidthConstraint; }

     @Override
     protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
         super.onTextChanged(text, start, lengthBefore, lengthAfter);

         setTextSize(TypedValue.COMPLEX_UNIT_PX, getVariableTextSize(text.toString()));
     }

     private void setTextSizeInternal(int unit, float size, boolean notifyListener) {
         final float oldTextSize = getTextSize();
         super.setTextSize(unit, size);
         if (notifyListener && mOnTextSizeChangeListener != null && getTextSize() != oldTextSize) {
             mOnTextSizeChangeListener.onTextSizeChanged(this, oldTextSize);
         }
     }

     @Override
     public void setTextSize(int unit, float size) {
         setTextSizeInternal(unit, size, true);
     }

     public float getMinimumTextSize() {
         return mMinimumTextSize;
     }

     public float getMaximumTextSize() {
         return mMaximumTextSize;
     }

     public float getVariableTextSize(CharSequence text) {
         if (mWidthConstraint < 0 || mMaximumTextSize <= mMinimumTextSize) {
             // Not measured, bail early.
             return getTextSize();
         }

         // Capture current paint state.
         mTempPaint.set(getPaint());

         // Step through increasing text sizes until the text would no longer fit.
         float lastFitTextSize = mMinimumTextSize;
         while (lastFitTextSize < mMaximumTextSize) {
             mTempPaint.setTextSize(Math.min(lastFitTextSize + mStepTextSize, mMaximumTextSize));
             if (Layout.getDesiredWidth(text, mTempPaint) > mWidthConstraint) {
                 break;
             }
             lastFitTextSize = mTempPaint.getTextSize();
         }

         return lastFitTextSize;
     }

     private static boolean startsWith(CharSequence whole, CharSequence prefix) {
         int wholeLen = whole.length();
         int prefixLen = prefix.length();
         if (prefixLen > wholeLen) {
             return false;
         }
         for (int i = 0; i < prefixLen; ++i) {
             if (prefix.charAt(i) != whole.charAt(i)) {
                 return false;
             }
         }
         return true;
     }

     /**
      * Functionally equivalent to setText(), but explicitly announce changes.
      * If the new text is an extension of the old one, announce the addition.
      * Otherwise, e.g. after deletion, announce the entire new text.
      */
     public void changeTextTo(CharSequence newText) {
         final CharSequence oldText = getText();
         if (startsWith(newText, oldText)) {
             final int newLen = newText.length();
             final int oldLen = oldText.length();
             if (newLen == oldLen + 1) {
                 // The algorithm for pronouncing a single character doesn't seem
                 // to respect our hints.  Don't give it the choice.
                 final char c = newText.charAt(oldLen);
                 final int id = KeyMaps.keyForChar(c);
                 final String descr = KeyMaps.toDescriptiveString(getContext(), id);
                 if (descr != null) {
                     announceForAccessibility(descr);
                 } else {
                     announceForAccessibility(String.valueOf(c));
                 }
             } else if (newLen > oldLen) {
                 announceForAccessibility(newText.subSequence(oldLen, newLen));
             }
         } else {
             announceForAccessibility(newText);
         }
         setText(newText);
     }

     public boolean stopActionMode() {
         if (mActionMode != null) {
             mActionMode.finish();
             return true;
         }
         return false;
     }

     public void setOnTextSizeChangeListener(OnTextSizeChangeListener listener) {
         mOnTextSizeChangeListener = listener;
     }

     public void setOnPasteListener(OnPasteListener listener) {
         mOnPasteListener = listener;
     }

     private void paste() {
         final ClipboardManager clipboard = (ClipboardManager) getContext()
                 .getSystemService(Context.CLIPBOARD_SERVICE);
         final ClipData primaryClip = clipboard.getPrimaryClip();
         if (primaryClip != null && mOnPasteListener != null) {
             mOnPasteListener.onPaste(primaryClip);
         }
     }

     public interface OnTextSizeChangeListener {
         void onTextSizeChanged(TextView textView, float oldSize);
     }

     public interface OnPasteListener {
         boolean onPaste(ClipData clip);
     }
 }
	/*
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.calculator2;

	import android.content.ClipData;
	import android.content.ClipboardManager;
	import android.content.Context;
	import android.content.res.TypedArray;
	import android.graphics.Rect;
	import android.text.Layout;
	import android.text.TextPaint;
	import android.text.method.ScrollingMovementMethod;
	import android.util.AttributeSet;
	import android.util.TypedValue;
	import android.view.ActionMode;
	import android.view.Menu;
	import android.view.MenuInflater;
	import android.view.MenuItem;
	import android.view.View;
	import android.widget.TextView;

	/**
	* TextView adapted for Calculator display.
	*/
	public class CalculatorText extends AlignedTextView implements View.OnLongClickListener {

	private final ActionMode.Callback2 mPasteActionModeCallback = new ActionMode.Callback2() {

	@Override
	public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
	if (item.getItemId() == R.id.menu_paste) {
	paste();
	mode.finish();
	return true;
	}
	return false;
	}

	@Override
	public boolean onCreateActionMode(ActionMode mode, Menu menu) {
	final ClipboardManager clipboard = (ClipboardManager) getContext()
	.getSystemService(Context.CLIPBOARD_SERVICE);
	if (clipboard.hasPrimaryClip()) {
	bringPointIntoView(length());
	MenuInflater inflater = mode.getMenuInflater();
	inflater.inflate(R.menu.paste, menu);
	return true;
	}
	// Prevents the selection action mode on double tap.
	return false;
	}

	@Override
	public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
	return false;
	}

	@Override
	public void onDestroyActionMode(ActionMode mode) {
	mActionMode = null;
	}

	@Override
	public void onGetContentRect(ActionMode mode, View view, Rect outRect) {
	super.onGetContentRect(mode, view, outRect);
	outRect.top += getTotalPaddingTop();
	outRect.right -= getTotalPaddingRight();
	outRect.bottom -= getTotalPaddingBottom();
	// Encourage menu positioning towards the right, possibly over formula.
	outRect.left = outRect.right;
	}
	};

	// Temporary paint for use in layout methods.
	private final TextPaint mTempPaint = new TextPaint();

	private final float mMaximumTextSize;
	private final float mMinimumTextSize;
	private final float mStepTextSize;

	private int mWidthConstraint = -1;

	private ActionMode mActionMode;

	private OnPasteListener mOnPasteListener;
	private OnTextSizeChangeListener mOnTextSizeChangeListener;

	public CalculatorText(Context context) {
	this(context, null /* attrs */);
	}

	public CalculatorText(Context context, AttributeSet attrs) {
	this(context, attrs, 0 /* defStyleAttr */);
	}

	public CalculatorText(Context context, AttributeSet attrs, int defStyleAttr) {
	super(context, attrs, defStyleAttr);

	final TypedArray a = context.obtainStyledAttributes(
	attrs, R.styleable.CalculatorText, defStyleAttr, 0);
	mMaximumTextSize = a.getDimension(
	R.styleable.CalculatorText_maxTextSize, getTextSize());
	mMinimumTextSize = a.getDimension(
	R.styleable.CalculatorText_minTextSize, getTextSize());
	mStepTextSize = a.getDimension(R.styleable.CalculatorText_stepTextSize,
	(mMaximumTextSize - mMinimumTextSize) / 3);
	a.recycle();

	// Allow scrolling by default.
	setMovementMethod(ScrollingMovementMethod.getInstance());

	// Reset the clickable flag, which is added when specifying a movement method.
	setClickable(false);

	// Add a long click to start the ActionMode manually.
	setOnLongClickListener(this);
	}

	@Override
	public boolean onLongClick(View v) {
	mActionMode = startActionMode(mPasteActionModeCallback, ActionMode.TYPE_FLOATING);
	return true;
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	// Re-calculate our textSize based on new width.
	final int width = MeasureSpec.getSize(widthMeasureSpec)
	- getPaddingLeft() - getPaddingRight();
	if (mWidthConstraint != width) {
	mWidthConstraint = width;

	if (!isLaidOut()) {
	// Prevent shrinking/resizing with our variable textSize.
	setTextSizeInternal(TypedValue.COMPLEX_UNIT_PX, mMaximumTextSize,
	false /* notifyListener */);
	setMinHeight(getLineHeight() + getCompoundPaddingBottom()
	+ getCompoundPaddingTop());
	}

	setTextSizeInternal(TypedValue.COMPLEX_UNIT_PX, getVariableTextSize(getText()),
	false);
	}

	super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	}

	public int getWidthConstraint() { return mWidthConstraint; }

	@Override
	protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
	super.onTextChanged(text, start, lengthBefore, lengthAfter);

	setTextSize(TypedValue.COMPLEX_UNIT_PX, getVariableTextSize(text.toString()));
	}

	private void setTextSizeInternal(int unit, float size, boolean notifyListener) {
	final float oldTextSize = getTextSize();
	super.setTextSize(unit, size);
	if (notifyListener && mOnTextSizeChangeListener != null && getTextSize() != oldTextSize) {
	mOnTextSizeChangeListener.onTextSizeChanged(this, oldTextSize);
	}
	}

	@Override
	public void setTextSize(int unit, float size) {
	setTextSizeInternal(unit, size, true);
	}

	public float getMinimumTextSize() {
	return mMinimumTextSize;
	}

	public float getMaximumTextSize() {
	return mMaximumTextSize;
	}

	public float getVariableTextSize(CharSequence text) {
	if (mWidthConstraint < 0 \|\| mMaximumTextSize <= mMinimumTextSize) {
	// Not measured, bail early.
	return getTextSize();
	}

	// Capture current paint state.
	mTempPaint.set(getPaint());

	// Step through increasing text sizes until the text would no longer fit.
	float lastFitTextSize = mMinimumTextSize;
	while (lastFitTextSize < mMaximumTextSize) {
	mTempPaint.setTextSize(Math.min(lastFitTextSize + mStepTextSize, mMaximumTextSize));
	if (Layout.getDesiredWidth(text, mTempPaint) > mWidthConstraint) {
	break;
	}
	lastFitTextSize = mTempPaint.getTextSize();
	}

	return lastFitTextSize;
	}

	private static boolean startsWith(CharSequence whole, CharSequence prefix) {
	int wholeLen = whole.length();
	int prefixLen = prefix.length();
	if (prefixLen > wholeLen) {
	return false;
	}
	for (int i = 0; i < prefixLen; ++i) {
	if (prefix.charAt(i) != whole.charAt(i)) {
	return false;
	}
	}
	return true;
	}

	/**
	* Functionally equivalent to setText(), but explicitly announce changes.
	* If the new text is an extension of the old one, announce the addition.
	* Otherwise, e.g. after deletion, announce the entire new text.
	*/
	public void changeTextTo(CharSequence newText) {
	final CharSequence oldText = getText();
	if (startsWith(newText, oldText)) {
	final int newLen = newText.length();
	final int oldLen = oldText.length();
	if (newLen == oldLen + 1) {
	// The algorithm for pronouncing a single character doesn't seem
	// to respect our hints. Don't give it the choice.
	final char c = newText.charAt(oldLen);
	final int id = KeyMaps.keyForChar(c);
	final String descr = KeyMaps.toDescriptiveString(getContext(), id);
	if (descr != null) {
	announceForAccessibility(descr);
	} else {
	announceForAccessibility(String.valueOf(c));
	}
	} else if (newLen > oldLen) {
	announceForAccessibility(newText.subSequence(oldLen, newLen));
	}
	} else {
	announceForAccessibility(newText);
	}
	setText(newText);
	}

	public boolean stopActionMode() {
	if (mActionMode != null) {
	mActionMode.finish();
	return true;
	}
	return false;
	}

	public void setOnTextSizeChangeListener(OnTextSizeChangeListener listener) {
	mOnTextSizeChangeListener = listener;
	}

	public void setOnPasteListener(OnPasteListener listener) {
	mOnPasteListener = listener;
	}

	private void paste() {
	final ClipboardManager clipboard = (ClipboardManager) getContext()
	.getSystemService(Context.CLIPBOARD_SERVICE);
	final ClipData primaryClip = clipboard.getPrimaryClip();
	if (primaryClip != null && mOnPasteListener != null) {
	mOnPasteListener.onPaste(primaryClip);
	}
	}

	public interface OnTextSizeChangeListener {
	void onTextSizeChanged(TextView textView, float oldSize);
	}

	public interface OnPasteListener {
	boolean onPaste(ClipData clip);
	}
	}