Android 将自定义视图调整为其父视图指定的最大大小
我正在编写一个自定义视图,希望在其中使用Android 将自定义视图调整为其父视图指定的最大大小,android,canvas,android-custom-view,Android,Canvas,Android Custom View,我正在编写一个自定义视图,希望在其中使用canvas.drawText()和Paint对象绘制一些文本 我希望这个视图能占据尽可能多的空间,同时保持比例 例如,让我的自定义视图为水平绘制的一系列4位数字,即1 2 3 4。 然后,对于某些宽度和高度规格,视图应如下所示: ---------------------- 1 2 3 4 ---------------------- 但对于更大的宽度和高度规格(如将手机旋转到横向模式,或只是从父视图获得更大的许可),它应该
canvas.drawText()
和Paint
对象绘制一些文本
我希望这个视图能占据尽可能多的空间,同时保持比例
例如,让我的自定义视图为水平绘制的一系列4位数字,即1 2 3 4。
然后,对于某些宽度和高度规格,视图应如下所示:
----------------------
1 2 3 4
----------------------
但对于更大的宽度和高度规格(如将手机旋转到横向模式,或只是从父视图获得更大的许可),它应该拉伸以适应可用空间,同时保持比例-数字的大小和它们之间的填充:
----------------------------------------
1 2 3 4
----------------------------------------
请想象一下,第二幅图中的数字更大,因为我不能发布图片,因为我的声誉很低
我的问题是:
为我的视图设置正确度量值的正确方法应该是什么?文本大小和填充
我还没有编写一些代码,但我想重写onMeasure()
并使用MeasureSpec.getSize()
。我很困惑-我不确定MeasureSpec.getSize()
是否是我应该处理的唯一约束-也许paint.measureText()
和画布大小本身也必须发挥作用,我没有太多的经验将所有这些结合起来使用
谢谢大家! 像这样扩展TextView(很抱歉,我借用了一些,写了一些,不是全部,但我没有原始版本的源代码)。特别是,我覆盖了“省略号”部分—您将需要—以在省略号出现和视图表现不理想之前适应所需的文本大小
import android.content.Context;
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;
public class StoryTextView extends TextView {
private String TAG = "StoryTextView";
// Minimum text size for this text view
public static float MIN_TEXT_SIZE;
// Interface for resize notifications
public interface OnTextResizeListener {
public void onTextResize(TextView textView, float oldSize, float newSize);
}
// 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 = 0.3f;
// Add ellipsis to text that overflows at the smallest text size
private boolean mAddEllipsis = true;
// Default constructor override
public StoryTextView(Context context) {
this(context, null);
}
// Default constructor when inflating from XML file
public StoryTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
// Default constructor override
public StoryTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
MIN_TEXT_SIZE = context.getResources().getDimension(R.dimen.textMinSizeStory);
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() {
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) {
if(changed || mNeedsResize) {
int widthLimit = (right - left) - getCompoundPaddingLeft() - getCompoundPaddingRight();
int heightLimit = (bottom - top) - getCompoundPaddingBottom() - getCompoundPaddingTop();
resizeText(widthLimit, heightLimit);
}
super.onLayout(changed, left, top, right, bottom);
}
/**
* 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
float targetTextSize = mMaxTextSize > 0 ? Math.min(mTextSize, mMaxTextSize) : mTextSize;
// 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 - 1, mMinTextSize);
textHeight = getTextHeight(text, textPaint, width, targetTextSize);
//Log.i(TAG, "checking text size: " + textHeight);
}
// 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
StaticLayout layout = new StaticLayout(text, textPaint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, false);
// Check that we have a least one line of rendered text
if(layout.getLineCount() > 0) {
// Since the line at the specific vertical position would be cut off,
// we must trim up to the previous line
int lastLine = layout.getLineForVertical(height) - 1;
// If the text would not even fit on a single line, clear it
if(lastLine < 0) {
setText("");
}
// Otherwise, trim to the previous line and add an ellipsis
else {
int start = layout.getLineStart(lastLine);
int end = layout.getLineEnd(lastLine);
float lineWidth = layout.getLineWidth(lastLine);
float ellipseWidth = textPaint.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);
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 paint, int width, float textSize) {
// Update the text paint object
paint.setTextSize(textSize);
// Measure using a static layout
StaticLayout layout = new StaticLayout(source, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return layout.getHeight();
}
}
导入android.content.Context;
导入android.text.Layout.Alignment;
导入android.text.StaticLayout;
导入android.text.TextPaint;
导入android.util.AttributeSet;
导入android.util.TypedValue;
导入android.widget.TextView;
公共类StoryTextView扩展了TextView{
私有字符串标记=“StoryTextView”;
//此文本视图的最小文本大小
公共静态浮动最小文本大小;
//调整大小通知的接口
公共接口OnTextResizeListener{
public void onTextResize(TextView TextView、float oldSize、float newSize);
}
//我们的椭圆弦
私有静态最终字符串mEllipsis=“…”;
//注册调整侦听器大小
私有OnTextResizeListener mTextResizeListener;
//文本和/或大小更改的标志,以强制调整大小
私有布尔值mNeedsResize=false;
//根据代码设置的文本大小。这是调整大小的起点
私有浮动mTextSize;
//起始文本大小的临时上限
私有浮点mMaxTextSize=0;
//文本大小的下限
私有浮点mMinTextSize=MIN\u TEXT\u SIZE;
//文本视图行距倍增器
私人浮动mSpacingMult=1.0f;
//文本视图附加行间距
私人浮动mSpacingAdd=0.3f;
//将省略号添加到以最小文本大小溢出的文本中
私有布尔mAddEllipsis=true;
//默认构造函数重写
公共故事文本视图(上下文){
这个(上下文,空);
}
//从XML文件膨胀时的默认构造函数
公共故事文本视图(上下文、属性集属性){
这(上下文,属性,0);
}
//默认构造函数重写
公共故事文本视图(上下文、属性集属性、int-defStyle){
超级(上下文、属性、定义样式);
MIN_TEXT_SIZE=context.getResources().getDimension(R.dimen.TextMinSizeStore);
mTextSize=getTextSize();
}
/**
*文本更改时,请将“强制调整大小”标志设置为true并重置文本大小。
*/
@凌驾
受保护的void onTextChanged(最终字符序列文本、最终整数开始、最终整数之前、最终整数之后){
mNeedsResize=true;
//由于此视图可以重用,因此最好重置文本大小
resetTextSize();
}
/**
*如果文字视图大小已更改,请将“强制调整大小”标志设置为true
*/
@凌驾
已更改尺寸的受保护空心(整数w、整数h、整数oldw、整数oldh){
如果(w!=oldw | | h!=oldh){
mNeedsResize=true;
}
}
/**
*注册侦听器以接收调整大小通知
*@param侦听器
*/
public void setOnResizeListener(OnTextResizeListener侦听器){
mTextResizeListener=监听器;
}
/**
*覆盖设置的文本大小以更新内部参考值
*/
@凌驾
公共void setTextSize(浮动大小){
super.setTextSize(大小);
mTextSize=getTextSize();
}
/**
*覆盖设置的文本大小以更新内部参考值
*/
@凌驾
公共void setTextSize(整数单位,浮点大小){
super.setTextSize(单位,大小);
mTextSize=getTextSize();
}
/**
*覆盖设置的行距以更新内部参考值
*/
@凌驾
公共void设置行间距(浮动添加、浮动多个){
super.setlinespace(添加,多个);
mSpacingMult=mult;
mSpacingAdd=添加;
}
/**
*设置文本大小上限并使视图无效
*@param maxTextSize
*/
公共void setMaxTextSize(浮动maxTextSize){
mmaxtsize=maxTextSize;
requestLayout();
使无效();
}
/**
*返回文本大小上限
*@返回
*/
公共浮点getMaxTextSize(){
返回mMaxTextSize;
}
/**
*设置较低的文本大小限制并使视图无效
*@param minTextSize
*/
公共void setMinTextSize(浮点minTextSize){
mMinTextSize=minTextSize;
requestLayout();
使无效();
}
/**
*返回较低的文本大小限制