Develop Reference

How to position the dropdown on a multi-line AutoCompleteTextView?

I am trying to customize the behavior of an AutoCompleteTextView, but I have run into some difficulties. My AutoCompleteTextView subclass is a multi-line edit text, and I want to be able to vertically position the dropdown (really a ListPopupWindow) so as to follow the user's cursor around.
I thought that if I can compute the difference between the top of the anchor view and the current line position, I could set the offset accordingly, but I must be doing something wrong along the way, because the dropdown isn't going quite where I want it to go. Can someone point out to me what I'm doing wrong in this code?
#Override
public void showDropDown() {
// Get the screen position of the cursor and set the vertical offset accordingly.
int[] screenPoint = new int[2];
getLocationOnScreen(screenPoint);
final Rect displayFrame = new Rect();
getWindowVisibleDisplayFrame(displayFrame);
int pos = getSelectionStart();
Layout layout = getLayout();
int line = layout.getLineForOffset(pos);
int lineTop = layout.getLineTop(Math.max(0,line - 1));
int lineBottom = layout.getLineBottom(line);
int availableSpaceAboveField = screenPoint[1] + lineTop - displayFrame.top;
int availableSpaceBelowField = displayFrame.bottom - screenPoint[1] - lineBottom;
int verticalOffset = -lineTop;
setDropDownVerticalOffset(verticalOffset);
super.showDropDown();
}

find string at pixel position in textview [duplicate]

I have a TextView with an OnTouchListener. What I want is the character index the user is pointing to when I get the MotionEvent. Is there any way to get to the underlying font metrics of the TextView?

Have you tried something like this:
Layout layout = this.getLayout();
if (layout != null)
{
int line = layout.getLineForVertical(y);
int offset = layout.getOffsetForHorizontal(line, x);
// At this point, "offset" should be what you want - the character index
}
Hope this helps...

I am not aware of a simple direct way to do this but you should be able to put something together using the Paint object of the TextView via a call to TextView.getPaint()
Once you have the paint object you will have access to the underlying FontMetrices via a call to Paint.getFontMetrics() and have access to other functions like Paint.measureText() Paint.getTextBounds(), and Paint.getTextWidths() for accessing the actual size of the displayed text.

While it generally works I had a few problems with the answer from Tony Blues.
Firstly getOffsetForHorizontal returns an offset even if the x coordinate is way beyond the last character of the line.
Secondly the returned character offset sometimes belongs to the next character, not the character directly underneath the pointer. Apparently the method returns the offset of the nearest cursor position. This may be to the left or to the right of the character depending on what's closer by.
My solution uses getPrimaryHorizontal instead to determine the cursor position of a certain offset and uses binary search to find the offset underneath the pointer's x coordinate.
public static int getCharacterOffset(TextView textView, int x, int y) {
x += textView.getScrollX() - textView.getTotalPaddingLeft();
y += textView.getScrollY() - textView.getTotalPaddingTop();
final Layout layout = textView.getLayout();
final int lineCount = layout.getLineCount();
if (lineCount == 0 || y < layout.getLineTop(0) || y >= layout.getLineBottom(lineCount - 1))
return -1;
final int line = layout.getLineForVertical(y);
if (x < layout.getLineLeft(line) || x >= layout.getLineRight(line))
return -1;
int start = layout.getLineStart(line);
int end = layout.getLineEnd(line);
while (end > start + 1) {
int middle = start + (end - start) / 2;
if (x >= layout.getPrimaryHorizontal(middle)) {
start = middle;
}
else {
end = middle;
}
}
return start;
}
Edit: This updated version works better with unnatural line breaks, when a long word does not fit in a line and gets split somewhere in the middle.
Caveats: In hyphenated texts, clicking on the hyphen at the end of a line return the index of the character next to it. Also this method does not work well with RTL texts.

Android EditText real content height

I have an EditText in Android. It has long content and it scrolls into pages
How can I find the real height of content, not just the visible area?
I tried this, but it just gives height of visible area:
EditText editor=(EditText)findViewById(R.id.ed1);
.
.
.
double H=editor.getHeight();
not H is 1150, not 10000 or something like that which is real height of content.

This is what I do:
EditText tv = ...;
if (Build.VERSION.SDK_INT >= 16) {
totalHeight = Math.round((tv.getLineCount() * (tv.getLineHeight() + tv.getLineSpacingExtra()) *
tv.getLineSpacingMultiplier())) + tv.getCompoundPaddingTop() + tv.getCompoundPaddingBottom();
} else {
totalHeight = tv.getLineCount() * tv.getLineHeight() + tv.getCompoundPaddingTop() + tv.getCompoundPaddingBottom();
}

You can do this in following steps
count the lines in the edit text get help from here
after that calculate the height(includeing top padding) of single line then simply multiply that number to get the real height of the text inside the editText

It was enough for me to call EditText.getLayout().getHeight();
I've just debugged an app where I need this functionality too:
int contentHeight = view.getTextArea().getLayout().getHeight();
int visibleAreaHeight = view.getTextArea().getHeight();
The values are:
contentHeight = 7531
visibleAreaHeight = 1408

Get current visible text in textview

I have a long passage in a TextView which is wrapped around by ScrollView. Is there any way to find the current visible text?
I can find the number of lines, line height in textview and also scrollx and scrolly from scrollview, but find the linkage to the current displayed text. Please help! Thanks.

It is simple to do this:
int start = textView.getLayout().getLineStart(0);
int end = textView.getLayout().getLineEnd(textView.getLineCount() - 1);
String displayed = textView.getText().toString().substring(start, end);

Here. Get the line number of the first displayed line. Then get the line number of the second displayed line. Then get the text and count the number of words.
private int getNumberOfWordsDisplayed() {
int start = textView.getLayout().getLineStart(getFirstLineIndex());
int end = textView.getLayout().getLineEnd(getLastLineIndex());
return textView.getText().toString().substring(start, end).split(" ").length;
}
/**
* Gets the first line that is visible on the screen.
*
* #return
*/
public int getFirstLineIndex() {
int scrollY = scrollView.getScrollY();
Layout layout = textView.getLayout();
if (layout != null) {
return layout.getLineForVertical(scrollY);
}
Log.d(TAG, "Layout is null: ");
return -1;
}
/**
* Gets the last visible line number on the screen.
* #return last line that is visible on the screen.
*/
public int getLastLineIndex() {
int height = scrollView.getHeight();
int scrollY = scrollView.getScrollY();
Layout layout = textView.getLayout();
if (layout != null) {
return layout.getLineForVertical(scrollY + height);
}
return -1;
}

Using textView.getLayout().getEllipsisStart(0) only works if android:singleLine="true"
Here is a solution that will work if android:maxLines is set:
public static String getVisibleText(TextView textView) {
// test that we have a textview and it has text
if (textView==null || TextUtils.isEmpty(textView.getText())) return null;
Layout l = textView.getLayout();
if (l!=null) {
// find the last visible position
int end = l.getLineEnd(textView.getMaxLines()-1);
// get only the text after that position
return textView.getText().toString().substring(0,end);
}
return null;
}
Remember: this works after the view is already loaded.
Usage:
textView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
textView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
Log.i("test" ,"VisibleText="+getVisibleText(textView));
}
});

You claim that you know scrollY, the current number of pixels scrolled. You also know the height of the window you're considering in pixels, so call that scrollViewHeight. Then
int scrollY; // This is your current scroll position in pixels.
int scrollViewHeight; // This is the height of your scrolling window.
TextView textView; // This is the TextView we're considering.
String text = (String) textView.getText();
int charsPerLine = text.length() / textView.getLineCount();
int lineHeight = textView.getLineHeight();
int startLine = scrollY / lineHeight;
int endLine = startLine + scrollViewHeight/lineHeight + 1;
int startChar = charsPerLine * startLine;
int endChar = charsPerLine * (endLine+1) + 1;
String approxVisibleString = text.substring(startChar, endChar);
It's an approximation, so use it as a last resort.

I also having about the same problem myself. I needed first visible line from textview currently visible in recyclerview. If you are trying to get currently displayed first line of textview in recyclerview you may use the following code:
TextView tv = (TextView) recyclerView.getChildAt(0); //gets current visible child view
// this is for top visible
//view or the textview directly
Rect r1 = new Rect();
tv.getHitRect(r1);//gets visible rect of textview
Layout l = tv.getLayout();
int line = l.getLineForVertical(-1 * r1.top);//first visible line
int start = l.getLineStart(line);//visible line start
int end = l.getLineEnd(line);//visible line end
String displayed = tv.getText().toString().substring(start, end);

try use getEllipsisStart()
int end = textView.getLayout().getEllipsisStart(0);

This depends on the use of Ellipsize in the TextView. Try this:
public String getVisibleText(TextView tv) {
int lastLine = tv.getMaxLines() < 1 || tv.getMaxLines() > tv.getLineCount() ? tv.getLineCount() : tv.getMaxLines();
if (tv.getEllipsize() != null && tv.getEllipsize().equals(TextUtils.TruncateAt.END)) {
int ellCount = tv.getLayout().getEllipsisCount(lastLine - 1);
if (ellCount > 0 && tv.length() > ellCount)
return tv.getText().toString().substring(0, tv_title.getText().length() - ellCount);
return tv.getText().toString();
} else {
int end = tv.getLayout().getLineEnd(lastLine - 1);
return tv.getText().toString().substring(0, end);
}
}
...
textView.post(new Runnable() {
#Override
public void run() {
Log.d(TAG, getVisibleText(textView));
}
});

Assuming you have the scrolled line number, you can use the following to get displayed text:
int start = tv.getLayout().getLineStart(scrolllinenumber);
int end=scrolllinenumber+tv.getLayout().getHeight();
String displayedtext = tv.getText().toString().substring(start, end);

How to find android TextView number of characters per line?

So I have a TextView in android that has the width of the whole length of the screen and a padding of dip 5. How can I calculate the number of characters that will fit a single line on the screen? I guess in other words, I'm trying to get the number of columns of a textview?
I considered manual calculation depending on textsize and width, but 1) don't know the correlation and 2) due to the padding in the units of dip, different screens will use different number of actual pixels to pad.
Overall Question: I am trying to use this to solve: if given a string how can I manually edit to string such that when the textview prints the string character by character, I will know when to start a word that won't fit on one line on the next. Note: I know that textview automatically puts words that won't fit onto the next line, however, since I'm printing character by character, like typing animation, textview doesn't know the word won't fit until it prints out the overflowing characters of that word.
Been searching everywhere for this...
Thanks!
Added solutions:
one possible solution:
public String measure2 (TextView t, String s) {
String u = "";
int start = 0;
int end = 1;
int space = 0;
boolean ellipsized = false;
float fwidth = t.getMeasuredWidth();
for(;;) {
//t.setText(s.substring(start, end));
float twidth = t.getPaint().measureText(s.substring(start, end));
if (twidth < fwidth){
if (end < s.length())
end++;
else {
if (!ellipsized)
return s;
return u + s.subSequence(start, end);
}
}
else {
ellipsized = true;
space = (u + s.substring(start, end)).lastIndexOf(" ");
if (space == -1)
space = end - 1;
u += s.subSequence(start, space) + "\n";
start = space + 1;
end = start + 1;
}
}
}
solution 2, but still uses solution1 sometimes:
public String measure3 (TextView t, String s) {
List<String> wlist = Arrays.asList(s.split(" "));
if (wlist.size() == 1)
return measure2(t, s);
String u = "";
int end = 1;
float fwidth = t.getMeasuredWidth();
for(;;) {
//t.setText(s.substring(start, end));
if (wlist.isEmpty())
return u;
String temp = listStr(wlist, end);
float twidth = t.getPaint().measureText(temp);
if (twidth < fwidth){
if (end < wlist.size())
end++;
else {
return u + temp;
}
}
else {
temp = listStr(wlist, end-1);
if (end == 1)
temp = measure2(t, temp);
if (wlist.isEmpty())
return u + temp;
else
u = u + temp + "\n";
wlist = wlist.subList(end - 1, wlist.size());
end = 1;
}
}
}
public String listStr (List<String> arr, int end) {
String s = "";
for (String e : arr.subList(0, end) ){
s = s + e + " ";
}
return s.trim();
}
I used the above code to generate off a original string s, a string u that would be printed. However, I think this approach is very inefficient. Is there another approach or a better algorithm? Note: there are some errors in measure3 that I fixed, but was too lazy to edit

Try this:
private boolean isTooLarge (TextView text, String newText) {
float textWidth = text.getPaint().measureText(newText);
return (textWidth >= text.getMeasuredWidth ());
}
Detecting how many characters fit will be impossible due to the variable width of the characters. The above function will test if a particular string will fit or not in the TextView. The content of newText should be all the characters in a particular line. If true, then start a new line (and using a new string to pass as parameter).
Answer to the comment:
because the app can be run in many systems is exactly why you need to measure it.
This is a way to solve your "overall question". What is the difference between using str.size()>numCol vs is too large? You will need to implement your animation (hint #1: insert a newline character)
as I said before when you start a new line, you start a new string (hint #2: if you extend TextView, you can implement all this in overriding setText). (hint #3: Keep track of the lines created with a static int lines; and use newString.split("\\r?\\n")[lines-1] to check for length).

You can get total line of Textview and get string for each characters by below code.Then you can set style to each line whichever you want.
I set first line bold.
private void setLayoutListner( final TextView textView ) {
textView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
textView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
final Layout layout = textView.getLayout();
// Loop over all the lines and do whatever you need with
// the width of the line
for (int i = 0; i < layout.getLineCount(); i++) {
int end = layout.getLineEnd(0);
SpannableString content = new SpannableString( textView.getText().toString() );
content.setSpan(new StyleSpan(android.graphics.Typeface.BOLD), 0, end, 0);
content.setSpan(new StyleSpan(android.graphics.Typeface.NORMAL), end, content.length(), 0);
textView.setText( content );
}
}
});
}
Try this way.You can apply multiple style this way.

I had the same issue and I calculated the number characters per line by 2 steps:
Step 1: Calculate the number of lines
val widthOfTvComment = widthOfScreen - marginLeft - marginRight
var bounds = Rect()
var paint = Paint()
paint.textSize = textSize
paint.getTextBounds(comment,0,comment.length,bounds)
val lines = ( bounds.width()/widthOfTvComment)
Step 2: Calculated the number characters per line
val charactersPerLine = comment.length / lines