android - 如何自动调整 TextView 中的文本大小以适应垂直和水平可用空间？

Question

我想知道是否有一种简单的方法可以在没有换行或重叠的情况下自动调整 TextView 中的文本大小以适应其可用空间(垂直和水平)。我的目标是在任何设备上使文本尽可能大。这应该适用于横向和纵向。

我几乎可以正常工作(仅在纵向模式下)，它看起来像这样:

myapp in portrait

简化的 javacode:

public class MainActivity extends Activity{

private TextView        mTV_veryTop;
private TextView        mTV_top;
private TextView        mTV_middle;
private TextView        mTV_bottomLeft;
private TextView        mTV_bottomRight;
private Boolean         resized = false;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.cockpit_layout);

    mTV_veryTop = (TextView) findViewById(R.id.veryTop);
    mTV_top = (TextView) findViewById(R.id.top);
    mTV_middle = (TextView) findViewById(R.id.middle);
    mTV_bottomLeft = (TextView) findViewById(R.id.bottomLeft);
    mTV_bottomRight = (TextView) findViewById(R.id.bottomRight);

}

@Override
public void onWindowFocusChanged(boolean hasFocus)
{
    // TODO Auto-generated method stub
    super.onWindowFocusChanged(hasFocus);

    if (resized == false)
    {

        shrinkTextToFit(mTV_veryTop.getWidth(), mTV_veryTop, 300, 10);  
        shrinkTextToFit(mTV_top.getWidth(), mTV_top, 300, 10);  
        shrinkTextToFit(mTV_middle.getWidth(), mTV_middle, 300, 10);    
        shrinkTextToFit(mTV_bottomLeft.getWidth(),mTV_bottomLeft, 300, 10); 
        shrinkTextToFit(mTV_bottomRight.getWidth(), mTV_bottomRight, 300, 10);  

        resized = true;
    }

}

public static void shrinkTextToFit(float availableWidth, TextView textView, float startingTextSize, float minimumTextSize)
{

    CharSequence text = textView.getText();
    float textSize = startingTextSize;
    textView.setTextSize(startingTextSize);

    while (text != (TextUtils.ellipsize(text, textView.getPaint(), availableWidth, TextUtils.TruncateAt.END)))
    {
        textSize -= 1;
        if (textSize < minimumTextSize)
        {
            break;
        }
        else
        {
            textView.setTextSize(textSize);
        }
    }
}

布局文件:

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000000"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/veryTop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1"
        android:gravity="center"
        android:text="very top"
        android:textColor="@android:color/white"
        android:textSize="500dp" >
    </TextView>

     <TextView
        android:id="@+id/top"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="5"
        android:gravity="center"
        android:text="top"
        android:textColor="@android:color/white"
        android:textSize="500dp" />

    <TextView
        android:id="@+id/middle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1"
        android:gravity="middle"
        android:text="N.A."
        android:textColor="@android:color/white"
        android:textSize="500dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="3"
        android:orientation="horizontal" >



        <TextView
            android:id="@+id/bottomLeft"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_weight="5"
            android:gravity="center"
         android:text="bottom left"
            android:textColor="@android:color/white"
            android:textSize="500dp" >
        </TextView>

        <TextView
            android:id="@+id/bottomRight"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:layout_weight="5"
            android:gravity="center"
            android:text="bottom right"
            android:textColor="@android:color/white"
            android:textSize="500dp" >
        </TextView>
    </LinearLayout>

</LinearLayout>

.......但这在风景中不起作用，甚至在肖像中也不完美(底部缺少一些像素)

我读过几篇这样的文章:

How to scale/resize text to fit a TextView?

Auto Scale TextView Text to Fit within Bounds

Scale text in a view to fit?

......并尝试了不同的方法/textView 类，但总有一些无法满足我的需要。

有什么帮助吗？

更新:

我不知道为什么我的问题被否决了，因为要找到一个类/ TextView (在“百万库”下)来满足我的所有要求并不容易。这是我需要的所有类(class)(可能对某人有帮助):

public class AutoResizeTextview extends TextView
{
    private interface SizeTester
    {
        /**
         * 
         * @param suggestedSize
         *            Size of text to be tested
         * @param availableSpace
         *            available space in which text must fit
         * @return an integer < 0 if after applying {@code suggestedSize} to
         *         text, it takes less space than {@code availableSpace}, > 0
         *         otherwise
         */
        public int onTestSize(int suggestedSize, RectF availableSpace);
    }

    private RectF               mTextRect           = new RectF();

    private RectF               mAvailableSpaceRect;

    private SparseIntArray      mTextCachedSizes;

    private TextPaint           mPaint;

    private float               mMaxTextSize;

    private float               mSpacingMult        = 1.0f;

    private float               mSpacingAdd         = 0.0f;

    private float               mMinTextSize        = 3;

    private int                 mWidthLimit;

    private static final int    NO_LINE_LIMIT       = -1;
    private int                 mMaxLines;

    private boolean             mEnableSizeCache    = true;
    private boolean             mInitiallized;

    public AutoResizeTextview(Context context)
    {
        super(context);
        initialize();
    }

    public AutoResizeTextview(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        initialize();
    }

    public AutoResizeTextview(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        initialize();
    }

    private void initialize()
    {
        mPaint = new TextPaint(getPaint());
        mMaxTextSize = getTextSize();
        mAvailableSpaceRect = new RectF();
        mTextCachedSizes = new SparseIntArray();
        if (mMaxLines == 0)
        {
            // no value was assigned during construction
            mMaxLines = NO_LINE_LIMIT;
        }
        mInitiallized = true;
    }

    @Override
    public void setText(final CharSequence text, BufferType type)
    {
        super.setText(text, type);
        adjustTextSize(text.toString());
    }

    @Override
    public void setTextSize(float size)
    {
        mMaxTextSize = size;
        mTextCachedSizes.clear();
        adjustTextSize(getText().toString());
    }

    @Override
    public void setMaxLines(int maxlines)
    {
        super.setMaxLines(maxlines);
        mMaxLines = maxlines;
        reAdjust();
    }

    public int getMaxLines()
    {
        return mMaxLines;
    }

    @Override
    public void setSingleLine()
    {
        super.setSingleLine();
        mMaxLines = 1;
        reAdjust();
    }

    @Override
    public void setSingleLine(boolean singleLine)
    {
        super.setSingleLine(singleLine);
        if (singleLine)
        {
            mMaxLines = 1;
        }
        else
        {
            mMaxLines = NO_LINE_LIMIT;
        }
        reAdjust();
    }

    @Override
    public void setLines(int lines)
    {
        super.setLines(lines);
        mMaxLines = lines;
        reAdjust();
    }

    @Override
    public void setTextSize(int unit, float size)
    {
        Context c = getContext();
        Resources r;

        if (c == null)
            r = Resources.getSystem();
        else
            r = c.getResources();
        mMaxTextSize = TypedValue.applyDimension(unit, size, r.getDisplayMetrics());
        mTextCachedSizes.clear();
        adjustTextSize(getText().toString());
    }

    @Override
    public void setLineSpacing(float add, float mult)
    {
        super.setLineSpacing(add, mult);
        mSpacingMult = mult;
        mSpacingAdd = add;
    }

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

    private void reAdjust()
    {
        adjustTextSize(getText().toString());
    }

    private void adjustTextSize(String string)
    {
        if (!mInitiallized)
        {
            return;
        }
        int startSize = (int) mMinTextSize;
        int heightLimit = getMeasuredHeight() - getCompoundPaddingBottom() - getCompoundPaddingTop();
        mWidthLimit = getMeasuredWidth() - getCompoundPaddingLeft() - getCompoundPaddingRight();
        mAvailableSpaceRect.right = mWidthLimit;
        mAvailableSpaceRect.bottom = heightLimit;
        super.setTextSize(TypedValue.COMPLEX_UNIT_PX, efficientTextSizeSearch(startSize, (int) mMaxTextSize, mSizeTester, mAvailableSpaceRect));
    }

    private final SizeTester    mSizeTester = new SizeTester()
    {
        @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
        @Override
        public int onTestSize(int suggestedSize, RectF availableSPace)
        {
            mPaint.setTextSize(suggestedSize);
            String text = getText().toString();
            boolean singleline = getMaxLines() == 1;
            // if (singleline) {    //my comment-out
            // mTextRect.bottom = mPaint.getFontSpacing();  //my comment-out
            // mTextRect.right = mPaint.measureText(text);  //my comment-out
            // } else { //my comment-out
            StaticLayout layout = new StaticLayout(text, mPaint, mWidthLimit, Alignment.ALIGN_NORMAL, mSpacingMult,
                    mSpacingAdd, true);
            // return early if we have more lines
            if (getMaxLines() != NO_LINE_LIMIT && layout.getLineCount() > getMaxLines())
            {
                return 1;
            }
            mTextRect.bottom = layout.getHeight();
            int maxWidth = -1;
            for (int i = 0; i < layout.getLineCount(); i++)
            {
                if (maxWidth < layout.getLineWidth(i))
                {
                    maxWidth = (int) layout.getLineWidth(i);
                }
            }
            mTextRect.right = maxWidth;
            // }    //my comment-out

            mTextRect.offsetTo(0, 0);
            if (availableSPace.contains(mTextRect))
            {
                // may be too small, don't worry we will find the best match
                return -1;
            }
            else
            {
                // too big
                return 1;
            }
        }
    };

    /**
     * Enables or disables size caching, enabling it will improve performance
     * where you are animating a value inside TextView. This stores the font
     * size against getText().length() Be careful though while enabling it as 0
     * takes more space than 1 on some fonts and so on.
     * 
     * @param enable
     *            enable font size caching
     */
    public void enableSizeCache(boolean enable)
    {
        mEnableSizeCache = enable;
        mTextCachedSizes.clear();
        adjustTextSize(getText().toString());
    }

    private int efficientTextSizeSearch(int start, int end, SizeTester sizeTester, RectF availableSpace)
    {
        if (!mEnableSizeCache)
        {
            return binarySearch(start, end, sizeTester, availableSpace);
        }
        String text = getText().toString();
        int key = text == null ? 0 : text.length();
        int size = mTextCachedSizes.get(key);
        if (size != 0)
        {
            return size;
        }
        size = binarySearch(start, end, sizeTester, availableSpace);
        mTextCachedSizes.put(key, size);
        return size;
    }

    private static int binarySearch(int start, int end, SizeTester sizeTester, RectF availableSpace)
    {
        int lastBest = start;
        int lo = start;
        int hi = end - 1;
        int mid = 0;
        while (lo <= hi)
        {
            mid = (lo + hi) >>> 1;
            int midValCmp = sizeTester.onTestSize(mid, availableSpace);
            if (midValCmp < 0)
            {
                lastBest = lo;
                lo = mid + 1;
            }
            else
                if (midValCmp > 0)
                {
                    hi = mid - 1;
                    lastBest = hi;
                }
                else
                {
                    return mid;
                }
        }
        // make sure to return last best
        // this is what should always be returned
        return lastBest;

    }

    @Override
    protected void onTextChanged(final CharSequence text, final int start, final int before, final int after)
    {
        super.onTextChanged(text, start, before, after);
        reAdjust();
    }

    @Override
    protected void onSizeChanged(int width, int height, int oldwidth, int oldheight)
    {
        mTextCachedSizes.clear();
        super.onSizeChanged(width, height, oldwidth, oldheight);
        if (width != oldwidth || height != oldheight)
        {
            reAdjust();
        }
    }
}

Answer 1

已经有大约一百万个图书馆提供此服务。查看它们的实现，或者直接使用它。

https://github.com/grantland/android-autofittextview

https://bitbucket.org/ankri/autoscaletextview/src

Google 上的 5 秒给了我这些。