如何布局文本以在图像周围流动

Question

你能否告诉我是否有办法在图像周围布置文字？像这样:

------  text text text
|    |  text text text
-----   text text text
text text text text
text text text text

我从android开发者那里得到了关于这个问题的回复.但我不确定通过自己的TextView版本意味着什么？感谢任何提示.

2010年2月8日星期一晚上11:05,Romain Guy写道:

嗨,

仅使用提供的小部件和布局无法做到这一点.您可以编写自己的TextView版本来执行此操作,这应该不难.

Answer 1

现在有可能,但仅适用于版本高于或等于2.2的手机,使用android.text.style.LeadingMarginSpan.LeadingMarginSpan2API 8中提供的界面.

下面是文章,而不是英语,虽然,但你可以直接从下载示例的源代码在这里.

如果要使应用程序与旧设备兼容,则可以显示不带浮动文本的不同布局.这是一个例子:

布局(旧版本的默认设置,将以编程方式更改为新版本)

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <ImageView 
            android:id="@+id/thumbnail_view"
            android:src="@drawable/icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

    <TextView android:id="@+id/message_view"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_toRightOf="@id/thumbnail_view"
            android:textSize="18sp"
            android:text="@string/text" />
</RelativeLayout>

助手班

class FlowTextHelper {

    private static boolean mNewClassAvailable;

    static {
        if (Integer.parseInt(Build.VERSION.SDK) >= 8) { // Froyo 2.2, API level 8
           mNewClassAvailable = true;
        }
    }

    public static void tryFlowText(String text, View thumbnailView, TextView messageView, Display display){
        // There is nothing I can do for older versions, so just return
        if(!mNewClassAvailable) return;

        // Get height and width of the image and height of the text line
        thumbnailView.measure(display.getWidth(), display.getHeight());
        int height = thumbnailView.getMeasuredHeight();
        int width = thumbnailView.getMeasuredWidth();
        float textLineHeight = messageView.getPaint().getTextSize();

        // Set the span according to the number of lines and width of the image
        int lines = (int)FloatMath.ceil(height / textLineHeight);
        //For an html text you can use this line: SpannableStringBuilder ss = (SpannableStringBuilder)Html.fromHtml(text);
        SpannableString ss = new SpannableString(text);
        ss.setSpan(new MyLeadingMarginSpan2(lines, width), 0, ss.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        messageView.setText(ss);

        // Align the text with the image by removing the rule that the text is to the right of the image
        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)messageView.getLayoutParams();
        int[]rules = params.getRules();
        rules[RelativeLayout.RIGHT_OF] = 0;
    }
}

MyLeadingMarginSpan2类(更新为支持API 21)

public class MyLeadingMarginSpan2 implements LeadingMarginSpan2 {
    private int margin;
    private int lines;
    private boolean wasDrawCalled = false;
    private int drawLineCount = 0;

    public MyLeadingMarginSpan2(int lines, int margin) {
        this.margin = margin;
        this.lines = lines;
    }

    @Override
    public int getLeadingMargin(boolean first) {
        boolean isFirstMargin = first;
        // a different algorithm for api 21+
        if (Build.VERSION.SDK_INT >= 21) {
            this.drawLineCount = this.wasDrawCalled ? this.drawLineCount + 1 : 0;
            this.wasDrawCalled = false;
            isFirstMargin = this.drawLineCount <= this.lines;
        }

        return isFirstMargin ? this.margin : 0;
    }

    @Override
    public void drawLeadingMargin(Canvas c, Paint p, int x, int dir, int top, int baseline, int bottom, CharSequence text, int start, int end, boolean first, Layout layout) {
        this.wasDrawCalled = true;
    }

    @Override
    public int getLeadingMarginLineCount() {
        return this.lines;
    }
}

用法示例

ImageView thumbnailView = (ImageView) findViewById(R.id.thumbnail_view);
TextView messageView = (TextView) findViewById(R.id.message_view);
String text = getString(R.string.text);

Display display = getWindowManager().getDefaultDisplay();
FlowTextHelper.tryFlowText(text, thumbnailView, messageView, display);

这就是应用程序在Android 2.2设备上的外观:

这适用于Android 2.1设备:

Answer 2

如今，您可以使用库：https : //github.com/deano2390/FlowTextView。像这样：

<uk.co.deanwild.flowtextview.FlowTextView
    android:id="@+id/ftv"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" >

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:padding="10dip"
            android:src="@drawable/android"/>
</uk.co.deanwild.flowtextview.FlowTextView>

Answer 3

这是FlowTextHelper的改进(来自vorrtex的回复).我添加了在文本和图像之间添加额外填充的可能性,并改进了行计算以考虑填充.请享用!

public class FlowTextHelper {
   private static boolean mNewClassAvailable;

   /* class initialization fails when this throws an exception */
   static {
       try {
           Class.forName("android.text.style.LeadingMarginSpan$LeadingMarginSpan2");
           mNewClassAvailable = true;
       } catch (Exception ex) {
           mNewClassAvailable = false;
       }
   }

   public static void tryFlowText(String text, View thumbnailView, TextView messageView, Display display, int addPadding){
       // There is nothing I can do for older versions, so just return
       if(!mNewClassAvailable) return;



       // Get height and width of the image and height of the text line
        thumbnailView.measure(display.getWidth(), display.getHeight());
        int height = thumbnailView.getMeasuredHeight();
        int width = thumbnailView.getMeasuredWidth() + addPadding;
        messageView.measure(width, height); //to allow getTotalPaddingTop
        int padding = messageView.getTotalPaddingTop();
        float textLineHeight = messageView.getPaint().getTextSize();

        // Set the span according to the number of lines and width of the image
        int lines =  (int)Math.round((height - padding) / textLineHeight);
        SpannableString ss = new SpannableString(text);
        //For an html text you can use this line: SpannableStringBuilder ss = (SpannableStringBuilder)Html.fromHtml(text);
        ss.setSpan(new MyLeadingMarginSpan2(lines, width), 0, ss.length(), 0);
        messageView.setText(ss);

        // Align the text with the image by removing the rule that the text is to the right of the image
        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)messageView.getLayoutParams();
        int[]rules = params.getRules();
        rules[RelativeLayout.RIGHT_OF] = 0;
   }


}

Answer 4

“但我不确定他说做我自己的 TextView 版本是什么意思？”

他的意思是您可以扩展 android.widget.TextView 类（或 Canvas 或其他可渲染表面）并实现您自己的重写版本，该版本允许嵌入图像并在其周围流动文本。

这可能是相当大量的工作，具体取决于您的通用程度。