Question

我在这里解决了我以前的问题：

Can not set gravity with setGravity vertically programatically. Is this an android bug or feature?

基本上我有一个自定义Button，里面有AutoResizeTextView。我想动画按钮并垂直居中文本视图。我通过测量和使用布局和onLayout方法解决了它。它在大多数设备上都能正常工作。

但是在某些设备上，在AutoResizeTextView内部的文本上方有一个额外的填充，无论如何我无法删除。设备表现不佳的是Kindle Fire和三星Galaxy Tab2 7. Nook Color，摩托罗拉Xoom和我的摩托罗拉Defy（CyanogenMod 10）上的布局正常。

我创建了一个示例项目来演示问题。它包括3个类和一个布局文件：

activity_main.xml中：

<RelativeLayout 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"
tools:context=".MainActivity" >

<herrbert74.artvsample.MyButton
    android:id="@+id/textView1"
    android:layout_width="240dp"
    android:layout_height="60dp"
    android:background="@android:color/black"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/hello_world" />

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/textView1"
    android:layout_alignRight="@+id/textView1"
    android:layout_marginBottom="46dp"
    android:layout_marginRight="54dp"
    android:text="Button" />


</RelativeLayout>

修改了AutoResizeTextView.java：

package herrbert74.artvsample;

import android.content.Context;
import android.graphics.Canvas;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
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 = 10;

// Interface for resize notifications
public interface OnTextResizeListener {
    public void onTextResize(TextView textView, float oldSize, float newSize);
}

// Off screen canvas for text size rendering
private static final Canvas sTextResizeCanvas = new Canvas();

// Our ellipse string
private static final String mEllipsis = "...";

// 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;

// Text view line spacing multiplier
private float mSpacingMult = 1.0f;

// Text view additional line spacing
private float mSpacingAdd = 0.0f;

// Add ellipsis to text that overflows at the smallest text size
private boolean mAddEllipsis = true;

// 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) {
    mNeedsResize = true;
    // Since this view may be reused, it is good to reset the text size
    resetTextSize();
}

/**
 * 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();

}

/**
 * Override the set line spacing to update our internal reference values
 */
@Override
public void setLineSpacing(float add, float mult) {
    super.setLineSpacing(add, mult);
    mSpacingMult = mult;
    mSpacingAdd = add;
}

/**
 * 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;
}

/**
 * Set flag to add ellipsis to text that overflows at the smallest text size
 * 
 * @param addEllipsis
 */
public void setAddEllipsis(boolean addEllipsis) {
    mAddEllipsis = addEllipsis;
}

/**
 * Return flag to add ellipsis to text that overflows at the smallest text
 * size
 * 
 * @return
 */
public boolean getAddEllipsis() {
    return mAddEllipsis;
}

/**
 * Reset the text to the original size
 */
public void resetTextSize() {
    //ZBertalan:changed to mMaxTextSize
    super.setTextSize(TypedValue.COMPLEX_UNIT_PX, mMaxTextSize);
    //ZBertalan:swapped them
    //mMaxTextSize = mTextSize;
    mTextSize = mMaxTextSize;
}

/**
 * Resize text after measuring ZBertalan: I commented this out because I
 * need to resize the text in onMeasure, to layout the textview based on
 * it's size
 */
/*
 * @Override protected void onLayout(boolean changed, int left, int top, int
 * right, int bottom) { if(changed || mNeedsResize) { int widthLimit =
 * (right - left) - getCompoundPaddingLeft() - getCompoundPaddingRight();
 * int heightLimit = (bottom - top) - getCompoundPaddingBottom() -
 * getCompoundPaddingTop(); //og.d("AnswerView", "inside ARTV.onLayout() " +
 * ); resizeText(widthLimit, heightLimit); } super.onLayout(changed, left,
 * top, right, bottom); }
 */

/**
 * @author zsbertalan Moved some code here to resize the textview here and
 *         position it based on it's new size
 */
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    int newWidth = MeasureSpec.getSize(widthMeasureSpec);
    int newHeight = MeasureSpec.getSize(heightMeasureSpec);

    resizeText(newWidth, newHeight);

    TextPaint p = getPaint();
    newHeight = getTextHeight(getText(), p, newWidth, getTextSize());

    this.setMeasuredDimension(newWidth, newHeight);
}

/**
 * Resize the text size with default width and height
 */
public void resizeText() {
    int heightLimit = getHeight() - getPaddingBottom() - getPaddingTop();
    int widthLimit = getWidth() - getPaddingLeft() - getPaddingRight();
    resizeText(widthLimit, heightLimit);
}

/**
 * Resize the text size with specified width and height
 * 
 * @param width
 * @param height
 */
public void resizeText(int width, int height) {
    CharSequence text = getText();
    // 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;
    }

    // Get the text view's paint object
    TextPaint textPaint = getPaint();

    // Store the current text size
    float oldTextSize = textPaint.getTextSize();
    // If there is a max text size set, use the lesser of that and the
    // default text size
    //ZBertalan: Bollocks. I changed to use mMaxTextSize all the time
    //float targetTextSize = mMaxTextSize > 0 ? Math.min(mTextSize, mMaxTextSize) : mTextSize;
    float targetTextSize = mMaxTextSize;

    // Get the required text height
    int textHeight = getTextHeight(text, textPaint, width, targetTextSize);

    // Until we either fit within our text view or we had reached our min
    // text size, incrementally try smaller sizes
    while (textHeight > height && targetTextSize > mMinTextSize) {
        targetTextSize = Math.max(targetTextSize - 2, mMinTextSize);
        textHeight = getTextHeight(text, textPaint, width, targetTextSize);
    }

    // If we had reached our minimum text size and still don't fit, append
    // an ellipsis
    if (mAddEllipsis && targetTextSize == mMinTextSize
            && textHeight > height) {
        // Draw using a static layout
        TextPaint paint = new TextPaint(textPaint);
        StaticLayout layout = new StaticLayout(text, paint, width,
                Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, false);
        layout.draw(sTextResizeCanvas);
        int lastLine = layout.getLineForVertical(height) - 1;
        int start = layout.getLineStart(lastLine);
        int end = layout.getLineEnd(lastLine);
        float lineWidth = layout.getLineWidth(lastLine);
        float ellipseWidth = paint.measureText(mEllipsis);

        // Trim characters off until we have enough room to draw the
        // ellipsis
        while (width < lineWidth + ellipseWidth) {
            lineWidth = textPaint.measureText(text.subSequence(start,
                    --end + 1).toString());
        }
        setText(text.subSequence(0, end) + mEllipsis);

    }

    // Some devices try to auto adjust line spacing, so force default line
    // spacing
    // and invalidate the layout as a side effect
    // textPaint.setTextSize(targetTextSize);
    setTextSize(TypedValue.COMPLEX_UNIT_PX, targetTextSize);
    setLineSpacing(mSpacingAdd, mSpacingMult);

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

    // Reset force resize flag
    mNeedsResize = false;
}

// Set the text size of the text paint object and use a static layout to
// render text off screen before measuring
private int getTextHeight(CharSequence source, TextPaint originalPaint, int width,
        float textSize) {
    TextPaint paint = new TextPaint(originalPaint);
    // Update the text paint object
    paint.setTextSize(textSize);
    // Draw using a static layout
    StaticLayout layout = new StaticLayout(source, paint, width,
            Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
    layout.draw(sTextResizeCanvas);
    return layout.getHeight();
}

}

MyButton.java：包herrbert74.artvsample;

import android.content.Context;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.WindowManager;
import android.widget.LinearLayout;

public class MyButton extends LinearLayout {
private AutoResizeTextView tv;
Context ctx;

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    AutoResizeTextView tv = (AutoResizeTextView) getChildAt(0);
    int padding = getHeight() / 8;
    int left = padding;
    int top = (getHeight() - tv.getMeasuredHeight()) / 2;
    int right = padding + tv.getMeasuredWidth();
    int bottom = getHeight() / 2 + tv.getMeasuredHeight() / 2;
    tv.layout(left, top, right, bottom);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    int w = MeasureSpec.getSize(widthMeasureSpec);
    int h = MeasureSpec.getSize(heightMeasureSpec);

    if (w == 0) {
        WindowManager wm = (WindowManager) ctx
                .getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics metrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(metrics);
        w = metrics.widthPixels;
        h = metrics.heightPixels;
    }
    tv.measure(MeasureSpec.makeMeasureSpec(w - 40, MeasureSpec.AT_MOST),
            MeasureSpec.makeMeasureSpec(h - 20, MeasureSpec.AT_MOST));
    setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec),
            MeasureSpec.getSize(heightMeasureSpec));
}

public MyButton(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
    tv = new AutoResizeTextView(context);
    tv.setMaxTextSize(54);
    tv.setTextColor(context.getResources().getColor(android.R.color.white));
    tv.setClickable(true);
    tv.setBackgroundResource(android.R.color.darker_gray);
    addView(tv);
}

public MyButton(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs);
    ctx = context;
}

protected MyButton(Context context) {
    super(context, null);

}

public void setText(String text) {
    tv.setText(text);
}

public String getText() {
    return tv.getText().toString();
}

public void setTextSize(float f) {
    tv.setTextSize(f);
}
}

MainActivity.java：包herrbert74.artvsample;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {
int x;
MyButton tv;

@Override
protected void onCreate(Bundle savedInstanceState) {
    x = -1;
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final String[] texts = { "normal text", "a bit longer text", "even longer text by a word", "Long. Longest text ever. Long. Long." };
    tv = (MyButton) findViewById(R.id.textView1);
    Button b = (Button) findViewById(R.id.button1);
    b.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            if (x < texts.length - 1)
                x++;
            else
                x = 0;
            tv.setText(texts[x]);
            Log.d("AnswerView", "Text: " + texts[x]);
        }

    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

}

在示例项目中，有一个用于更改文本的按钮。起初没有文字，然后文本越来越长。你可以看到图片上的差异。

按钮背景为黑色，文本视图背景为灰色。

以下是带有正确按钮的Defy文本视图：

Defy without text First text Second text Third text Fourth text

请注意，在Kindle上，textview已声称某个地方没有文字！ Kindle Fire上的布局错误：

enter image description here First text Second text Third text Fourth text

在myButton构造函数中，我尝试了以下无效：

tv.setPadding(0, 0, 0, 0);
tv.setLineSpacing(0f, 1f);
tv.setCompoundDrawablePadding(0);
tv.setCompoundDrawablesWithIntrinsicBounds(null, null, null, null);
tv.setCompoundDrawablesWithIntrinsicBounds(0, 0, 0, 0);

自定义视图中的不需要的填充在某些设备上使用AutoresizeTextView

0 个答案: