How to layout text to flow around an image

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"But I am not sure what he means by doing my own version of TextView?"

He means that you can extend the class android.widget.TextView (or Canvas or some other renderable surface) and implement your own overriding version that allows embedded images with text flowing around them.

This could be quite a lot of work depending on how general you make it.

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Now it is possible, but only for phones with version higher or equal 2.2 by using the android.text.style.LeadingMarginSpan.LeadingMarginSpan2 interface which is available in API 8.

Here is the article, not in English though, but you can download the source code of the example directly from here.

If you want to make your application compatible with older devices, you can display a different layout without a floating text. Here is an example:

Layout (default for older versions, will be changed programmatically for newer versions)

<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>

The helper class

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;
}
}

The MyLeadingMarginSpan2 class (updated to support 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;
}
}

Example of the usage

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);

This is how the application looks on the Android 2.2 device: Android 2.2 the text flows around the image

And this is for the Android 2.1 device:

Android 2.1 the text is situated near the image

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Here's an improvement for the FlowTextHelper (from vorrtex's reply). I added the possibility to add extra padding between the text and the image and improved the line calculation to also take padding into account. Enjoy!

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;
}




}

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This question seems to same as my question How to fill the empty spaces with content below the Image in android

I found the solution using flowtext library please find the first answer it might help you so far

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Vorrtex and Ronen's answers are working for me except for one detail - After wrapping text around the image there was a weird "negative" margin below the image and on the opposite side. I figured out that when setting the span on the SpannableString I changed

ss.setSpan(new MyLeadingMarginSpan2(lines, width), 0, ss.length(), 0);

to

ss.setSpan(new MyLeadingMarginSpan2(lines, width), 0, lines, 0);

which stopped the span after the image. Might not be necessary in all cases but thought I would share.

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I can offer more comfortable constructor for The MyLeadingMarginSpan2 class

    MyLeadingMarginSpan2(Context cc,int textSize,int height,int width) {
int pixelsInLine=(int) (textSize*cc.getResources().getDisplayMetrics().scaledDensity);
if (pixelsInLine>0 && height>0) {
this.lines=height/pixelsInLine;
} else  {
this.lines=0;
}
this.margin=width;
}

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Nowadays you can use library: https://github.com/deano2390/FlowTextView . Like this:

<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>

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vorrtex's answer didn't work for me but I took a lot from it and came up with my own solution. Here it is:

package ie.moses.keepitlocal.util;


import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.support.annotation.IntRange;
import android.text.Layout;
import android.text.style.LeadingMarginSpan;
import android.view.View;
import android.widget.TextView;


import ie.moses.keepitlocal.util.MeasurementUtils;
import ie.moses.keepitlocal.util.TextUtils;


import static com.google.common.base.Preconditions.checkArgument;


public class WrapViewSpan implements LeadingMarginSpan.LeadingMarginSpan2 {


private final Context _context;
private final int _lineCount;
private int _leadingMargin;
private int _padding;


public WrapViewSpan(View wrapeeView, TextView wrappingView) {
this(wrapeeView, wrappingView, 0);
}


/**
* @param padding Padding in DIP.
*/
public WrapViewSpan(View wrapeeView, TextView wrappingView, @IntRange(from = 0) int padding) {
_context = wrapeeView.getContext();
setPadding(padding);


int wrapeeHeight = wrapeeView.getHeight();
float lineHeight = TextUtils.getLineHeight(wrappingView);


int lineCnt = 0;
float linesHeight = 0F;
while ((linesHeight += lineHeight) <= wrapeeHeight) {
lineCnt++;
}


_lineCount = lineCnt;
_leadingMargin = wrapeeView.getWidth();
}


public void setPadding(@IntRange(from = 0) int paddingDp) {
checkArgument(paddingDp >= 0, "padding cannot be negative");
_padding = (int) MeasurementUtils.dpiToPixels(_context, paddingDp);
}


@Override
public int getLeadingMarginLineCount() {
return _lineCount;
}


@Override
public int getLeadingMargin(boolean first) {
if (first) {
return _leadingMargin + _padding;
} else {
return _padding;
}
}


@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) {


}


}

and in my actual class where the span is used:

ViewTreeObserver headerViewTreeObserver = _headerView.getViewTreeObserver();
headerViewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
String descriptionText = _descriptionView.getText().toString();
SpannableString spannableDescriptionText = new SpannableString(descriptionText);
LeadingMarginSpan wrapHeaderSpan = new WrapViewSpan(_headerView, _descriptionView, 12);
spannableDescriptionText.setSpan(
wrapHeaderSpan,
0,
spannableDescriptionText.length(),
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE
);
_descriptionView.setText(spannableDescriptionText);
ViewTreeObserver headerViewTreeObserver = _headerView.getViewTreeObserver();
headerViewTreeObserver.removeOnGlobalLayoutListener(this);
}
});

I needed the global layout listener in order to get the right values for getWidth() and getHeight().

Here is the result:

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try this simple implementation using kotlin and androidx. first, create leading span helper class:

class LeadingSpan(private val line: Int, private val margin: Int) : LeadingMarginSpan.LeadingMarginSpan2 {


override fun drawLeadingMargin(canvas: Canvas?, paint: Paint?, x: Int, dir: Int, top: Int, baseline: Int, bottom: Int, text: CharSequence?, start: Int, end: Int, first: Boolean, layout: Layout?) {}


override fun getLeadingMargin(first: Boolean): Int =  if (first) margin else 0


override fun getLeadingMarginLineCount(): Int = line
}

Then create a layout using RelativeLayout :

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">


<TextView
android:id="@+id/about_desc"
android:text="@string/about_desc"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>


<androidx.appcompat.widget.AppCompatImageView
android:id="@+id/logo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>


</RelativeLayout>

and finally setting up in your activity or fragment like:

val about = view.findViewById<TextView>(R.id.about_desc)
val logoImage = ContextCompat.getDrawable(view.context, R.mipmap.ic_launcher) as Drawable
@Suppress("DEPRECATION")
view.findViewById<AppCompatImageView>(R.id.logo).setBackgroundDrawable(logoImage)
val spannableString = SpannableString(about.text)
spannableString.setSpan(Helpers.LeadingSpan(5, logoImage.intrinsicWidth + 10), 0, spannableString.length, 0)
about.text = spannableString

change number 5 in the Helpers.LeadingSpan(5, logoImage.intrinsicWidth + 10) according to your drawable height.