When I include the below XML
to layout file, I can see the below image. If you see it, you could 开发者_如何学Crealize that the TextView
has top and bottom space.
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="E1"
android:background="#ff00ff00"/>
I wish to remove the space. How to remove it? What is it called? If anyone has clue.. please let me know. Thanks in advance.
Try android:includeFontPadding="false"
to see if it helps. In my experience that will help a little bit, but there's no way of reducing the TextView dimensions to the exact pixel-perfect text size.
The only alternative, which may or may not give better results, is to cheat a bit and hard-wire the dimensions to match the text size, e.g. "24sp"
instead of "wrap_content"
for the height.
I had the same problem. Attribute android:includeFontPadding="false"
does not work for me. I've solved this problem in this way:
public class TextViewWithoutPaddings extends TextView {
private final Paint mPaint = new Paint();
private final Rect mBounds = new Rect();
public TextViewWithoutPaddings(Context context) {
super(context);
}
public TextViewWithoutPaddings(Context context, AttributeSet attrs) {
super(context, attrs);
}
public TextViewWithoutPaddings(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
protected void onDraw(@NonNull Canvas canvas) {
final String text = calculateTextParams();
final int left = mBounds.left;
final int bottom = mBounds.bottom;
mBounds.offset(-mBounds.left, -mBounds.top);
mPaint.setAntiAlias(true);
mPaint.setColor(getCurrentTextColor());
canvas.drawText(text, -left, mBounds.bottom - bottom, mPaint);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
calculateTextParams();
setMeasuredDimension(mBounds.width() + 1, -mBounds.top + 1);
}
private String calculateTextParams() {
final String text = getText().toString();
final int textLength = text.length();
mPaint.setTextSize(getTextSize());
mPaint.getTextBounds(text, 0, textLength, mBounds);
if (textLength == 0) {
mBounds.right = mBounds.left;
}
return text;
}
}
android:includeFontPadding="false"
is pretty good but it does not get it precisely. sometimes you want border line accuracy so you can figure it out yourself by applying negative margins:
try setting your bottom and top margins to a negative value.
something like this:
android:layout_marginTop="-5dp"
android:layout_marginBottom="-5dp"
adjust the values accordingly.
This is the code that saved our day. It was adapted using mono C# code from maksimko:
public class TopAlignedTextView extends TextView {
public TopAlignedTextView(Context context) {
super(context);
}
/*This is where the magic happens*/
@Override
protected void onDraw(Canvas canvas){
float offset = getTextSize() - getLineHeight();
canvas.translate(0, offset);
super.onDraw(canvas);
}
}
Still had to play around with textView.setIncludeFontPadding(false)
because we were aligning TextViews
with different font sizes.
I faced the same problem. Here's a good answer: How to align the text to top of TextView?
But code is little unfinished and don't support all font sizes. Change the line
int additionalPadding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 5, getContext().getResources().getDisplayMetrics());
to
int additionalPadding = getTextSize() - getLineHeight();
Complete C# code (mono) removes top offset:
public class TextControl : TextView {
public TextControl (Context context) : base (context)
{
SetIncludeFontPadding (false);
Gravity = GravityFlags.Top;
}
protected override void OnDraw (Android.Graphics.Canvas canvas)
{
if (base.Layout == null)
return;
Paint.Color = new Android.Graphics.Color (CurrentTextColor);
Paint.DrawableState = GetDrawableState ();
canvas.Save ();
var offset = TextSize - LineHeight;
canvas.Translate (0, offset);
base.Layout.Draw (canvas);
canvas.Restore ();
}
}
Just wanted to add to DynamicMind's answer that the reason why you see spacing around your TextViews is padding in 9-patch backgrounds they use by default.
9-patch technology allows you to specify a content area which is, effectively, padding. That padding is used unless you set the view's padding explicitly. E.g., when you programmatically set a 9-patch background to a view which had paddings set, they are overridden. And vise-versa, if you set paddings they override what was set by 9-patch background.
Unfortunately, in the XML layout it's not possible to determine the order of these operations. I think just removing the background from your TextViews would help:
android:background="@null"
public class TopAlignedTextView extends TextView {
public TopAlignedTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public TopAlignedTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs);
setIncludeFontPadding(false); //remove the font padding
setGravity(getGravity() | Gravity.TOP);
}
@Override
protected void onDraw(Canvas canvas) {
TextPaint textPaint = getPaint();
textPaint.setColor(getCurrentTextColor());
textPaint.drawableState = getDrawableState();
canvas.save();
//remove extra font padding
int yOffset = getHeight() - getBaseline();
canvas.translate(0, - yOffset / 2);
if (getLayout() != null) {
getLayout().draw(canvas);
}
canvas.restore();
}
}
Modified this answer a little bit to use kotlin class and extend AppCompatTextView
, trimming vertical padding.
It allows setting android:fontFamily
. Method calculateTextParams()
moved from onDraw()
for performance. Not tested for multiple lines of text:
import android.content.Context
import android.graphics.Canvas
import android.graphics.Rect
import android.util.AttributeSet
import androidx.appcompat.widget.AppCompatTextView
class NoPaddingTextView : AppCompatTextView
{
private val boundsRect = Rect()
private val textParams = calculateTextParams()
constructor(context : Context?)
: super(context)
constructor(context : Context?, attrs : AttributeSet?)
: super(context, attrs)
constructor(context : Context?, attrs : AttributeSet?, defStyleAttr : Int)
: super(context, attrs, defStyleAttr)
override fun onDraw(canvas : Canvas)
{
with(boundsRect) {
paint.isAntiAlias = true
paint.color = currentTextColor
canvas.drawText(textParams,
-left.toFloat(),
(-top - bottom).toFloat(),
paint)
}
}
override fun onMeasure(widthMeasureSpec : Int, heightMeasureSpec : Int)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
calculateTextParams()
setMeasuredDimension(boundsRect.width() + 1, -boundsRect.top + 1)
}
private fun calculateTextParams() : String
{
return text.toString()
.also {text ->
text.length.let {textLength ->
paint.textSize = textSize
paint.getTextBounds(text, 0, textLength, boundsRect)
if(textLength == 0) boundsRect.right = boundsRect.left
}
}
}
}
Have you defined a layout margin? For example:
android:layout_marginTop="5dp"
Otherwise, if your text view is wrapped inside a LinearLayout or other container, then that cold have either padding or a margin too.
android:background="@android:drawable/editbox_background"
use it according to you change it that you want editbox_background. because android provide some build in background like above code choose according to your requirement. May be it is help full to you.
Inside a LinearLayout the default padding might be an issue. Try setting it to 0dp. It worked for me.
The answer of TopAlignedTextView code:TopAlignedTextView@GitHub
use it by layout:
<com.github.captain_miao.view.TopAlignedTextView
android:id="@+id/text_a"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:text="@string/text_demo_a"
/>
My way for fixing this is pretty hacky, but I managed to get the text to sit where I wanted by setting the height of the text view as static and fiddling with it until it just barely fit the text. In my case, the font style I was using had a height of 64sp so I set the height of my textview to 50sp and it worked okay. I also had to set foreground_gravity to bottom.
android:includeFontPadding="false"
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