As shown in the picture:
1. The first step is to create a new CollapsibleTextView class that inherits from LinearLayout:
/**
* @author CJF
*/
public class CollapsibleTextView extends LinearLayout {
/**
* Default (expanded and hidden) text color blue
*/
private ForegroundColorSpan expandAndHideColorSpan = new ForegroundColorSpan(Color.parseColor("#3b76ec"));
/ **
* The default (content text) text color is black
*/
private ForegroundColorSpan textColorSpan = new ForegroundColorSpan(Color.parseColor("#000000"));
/**
* The text displays the maximum number of lines, the default is 1
*/
private int maxLines = 1;
/**
* flag
*/
private boolean flag, flag2, flag3;
/**
* text
*/
private String text;
/**
* Text length
*/
private int length;
private TextView mCollapsibleTextView;
public CollapsibleTextView(Context context) {
super(context);
}
public CollapsibleTextView(Context context, AttributeSet attrs) {
super(context, attrs);
View view = inflate (context, R.layout.layout_collapsible_textview, this);
mCollapsibleTextView = (TextView) view.findViewById(R.id.mCollapsibleTextView);
//Set textView to be clickable
mCollapsibleTextView.setMovementMethod(LinkMovementMethod.getInstance());
}
/**
* Provide external exposure The method is to set the text content, the maximum number of text display lines, (content text) text color, (expand and hide) text color
*
of
lines
* @param textColor (content text) text color
* @param expandAndHideColor (expand and hide) text color
*/
public void setText(String text, int maxLines, int textColor, int expandAndHideColor) {
this.text = text;
//Assignment text display The maximum number of lines, the minimum is 1
this.maxLines = Math.max(maxLines, 1);
//Get the length of the string
length = text.length();
//setText calls to set the flag to true
flag = true;
// When flag3 is false, set the maximum number of lines once
if (!flag3) {
//Set the default maximum number of lines
mCollapsibleTextView.setMaxLines(maxLines);
}
//set the text
mCollapsibleTextView.setText(text);
//Set (content text) text color
textColorSpan = new ForegroundColorSpan(ContextCompat.getColor(getContext(), textColor));
//Set (expand and hide) text color
expandAndHideColorSpan = new ForegroundColorSpan(ContextCompat.getColor(getContext(), expandAndHideColor));
//Re-request
layout requestLayout();
}
/**
*Text setting
* Set expand or hide
*
* @param count
* @param str
* @return
*/
private SpannableString getClickableSpan(int count, String str) {
//Create a new spannableString (set font color, monitor click, font size)
SpannableString span = new SpannableString(str);
//set text color when count == 0 and return
if (count == 0) {
//Set font size for content text
span.setSpan(new RelativeSizeSpan(1f), 0, str.length(), Spannable .SPAN_EXCLUSIVE_EXCLUSIVE);
//Content text setting font can be clicked and listen
span.setSpan(new TextListener(), 0, str.length(), Spanned.SPAN_MARK_MARK);
//Content text setting font color
span.setSpan(textColorSpan, 0 , str.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
//Return span
return span;
}
int maxLines = mCollapsibleTextView.getMaxLines();
if (maxLines == this.maxLines) {
//Set font size for content text
span.setSpan(new RelativeSizeSpan(1f), 0, count - 5, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
//Expand and hide setting font color
//Set the font of the content text to be clickable and listen
span.setSpan(new TextListener(), 0, count - 5, Spanned.SPAN_MARK_MARK);
//Set the font color of the content text
span.setSpan(textColorSpan, 0, count - 5, Spannable .SPAN_EXCLUSIVE_EXCLUSIVE);
//Expand and hide setting font size
span.setSpan(new RelativeSizeSpan(1.1f), count - 5, count, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
//Expand and hide setting font can be clicked and listen
span.setSpan(new ExpandAndHideListener(), count - 5, count, Spanned.SPAN_MARK_MARK);
span.setSpan(expandAndHideColorSpan, count - 5, count, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
} else {
//Content text set font size
span.setSpan(new RelativeSizeSpan(1f), 0, count, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
//Content text setting font can be clicked and listen
span.setSpan(new TextListener(), 0, count, Spanned.SPAN_MARK_MARK);
//Content Text set font color
span.setSpan(textColorSpan, 0, count, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
// Expand and hide set font size
span.setSpan(new RelativeSizeSpan(1.1f), count, count + 3, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
/ / expand and hide set font clickable and listen
span.setSpan(new ExpandAndHideListener(), count, count + 3, Spanned.SPAN_MARK_MARK);
//Expand with hidden setting font color
span.setSpan(expandAndHideColorSpan, count, count + 3, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}
//Return span
return span;
}
/**
* 1. Expand and hide click events
* 2. (Click events for content text and expand and hide text click events can be used all or only one here)
* /
private class ExpandAndHideListener extends ClickableSpan implements View.OnClickListener {
//Text click event
@Override
public void onClick(@NonNull View widget) {
//flag setting and re-request layout
flagSetting();
}
@Override
public void updateDrawState(@NonNull TextPaint ds) {
super.updateDrawState(ds);
ds.setUnderlineText(false);
}
}
/**
* 1. Click event of content text
* 2. (The click event of content text and the click event of expanding and hiding text can be used all or only one can be used here) */ private
class
TextListener extends ClickableSpan implements View.OnClickListener {
//Text click event
@Override
public void onClick(@NonNull View widget) {
//flag setting and re-request layout
flagSetting();
}
@Override
public void updateDrawState(@NonNull TextPaint ds) {
super.updateDrawState(ds);
ds.setUnderlineText(false);
}
}
/ **
* Flag setting and re-request layout
*/
private void flagSetting() {
flag = true;
if (flag3) {
//mCollapsibleTextView.getLineCount() <= defaultMaxLines returns true, otherwise false
flag2 = mCollapsibleTextView.getLineCount() <= maxLines;
//Re-request layout
requestLayout();
}
}
/**
* Layout setting
*
* @param changed
* @param l
* @param t
* @param r
* @param b
*/
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l , t, r, b);
//flag returns false
if (!flag) {
return;
}
//set to false
flag = false;
//flag2 is true expand
if (flag2) {
//expand state
mCollapsibleTextView.setMaxLines(Integer.MAX_VALUE);
//add "hidden" after the original string
String allText = text + "hidden";
SpannableString clickableSpan = getClickableSpan(length, allText);
mCollapsibleTextView.setText(clickableSpan);
flag3 = true;
} else {
//flag2 is false to judge mCollapsibleTextView.getLineCount() > defaultMaxLines
if (mCollapsibleTextView.getLineCount() > maxLines) {
//close Starting state
mCollapsibleTextView.setMaxLines(maxLines);
//Get the position of the last character of the first line
int lineEnd = mCollapsibleTextView.getLayout().getLineEnd(maxLines - 1);
//Intercept the characters of the first line and replace the last five characters with "...Expand"
String hiddenString = text.substring(0, lineEnd - 5) + "...expand";
SpannableString clickableSpan = getClickableSpan(lineEnd, hiddenString);
mCollapsibleTextView.setText(clickableSpan);
flag3 = true;
} else {
SpannableString clickableSpan = getClickableSpan(0, text );
mCollapsibleTextView.setText(clickableSpan);
}
}
}
}
2. The second step is to create a new layout file layout_collapsible_textview.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/mCollapsibleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@android:color/transparent"
android:text="内容"
android:textSize="14sp" />
</LinearLayout>
3. The third step is to quote in the layout, com.tq.recorder.widget.customView.CollapsibleTextView is my package name, replace it with your own :
<com.tq.recorder.widget.customView.CollapsibleTextView
android:id="@+id/mCollapsibleView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="top"
android:textSize="14sp" />
4. The fourth step is used in the code, both in the Activity and the adapter:
CollapsibleTextView view = findViewById(R.id.mCollapsibleView);
//Incoming text content, default number of lines to display, (content text) text color, (expand and hide) text color
view.setText("Incoming text content" , 1, Color.parseColor("#000000"), Color.parseColor("#3b76ec"));
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