圆形背景文字(如Instagram，ReplacementSpan)无法按要求工作 [英] Rounded Background text like Instagram, ReplacementSpan not working as required
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问题描述
我正尝试做类似于下面的Instagram的事情-
I was trying to do something similar to Instagram below -
但是我想要像Instagram这样的曲线-
But i want this curves like Instagram -
现在我陷入了另一个问题-
当我键入时.文本不会自动转到下一行，我必须按回车键，就像通常editText以固定宽度工作一样. (简而言之，multiline在ReplacementSpan上无法正常工作)
Now i am stuck in one more problem -
When i types,. text does not goes automatically to next line, I have to press return , like normally editText works in fixed width. (In short multiline is not working fine with ReplacementSpan)
下面是我所做的示例代码-
Below is sample code for what i have done -
public class EditextActivity extends AppCompatActivity {
EditText edittext;
RoundedBackgroundSpan roundedBackgroundSpan;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.editext_screen);
edittext=(EditText)findViewById(R.id.edittext);
// edittext.setText("Hello My name is Karandeep Atwal.\n\n Hii this is test");
roundedBackgroundSpan= new RoundedBackgroundSpan(Color.RED,Color.WHITE);
edittext.getText().setSpan(roundedBackgroundSpan, 0, edittext.getText().length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
}
public class RoundedBackgroundSpan extends ReplacementSpan implements LineHeightSpan {
private static final int CORNER_RADIUS = 15;
private static final int PADDING_X = 10;
private int mBackgroundColor;
private int mTextColor;
/**
* @param backgroundColor background color
* @param textColor text color
*/
public RoundedBackgroundSpan(int backgroundColor, int textColor) {
mBackgroundColor = backgroundColor;
mTextColor = textColor;
}
@Override
public int getSize(Paint paint, CharSequence text, int start, int end, Paint.FontMetricsInt fm) {
return (int) (PADDING_X + paint.measureText(text,start, end) + PADDING_X);
}
@Override
public void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint) {
float width = paint.measureText(text,start, end);
RectF rect = new RectF(x, top, x + width + 2 * PADDING_X, bottom);
paint.setColor(mBackgroundColor);
canvas.drawRoundRect(rect, CORNER_RADIUS, CORNER_RADIUS, paint);
paint.setColor(mTextColor);
canvas.drawText(text, start, end, x + PADDING_X, y, paint);
}
@Override
public void chooseHeight(CharSequence text, int start, int end, int spanstartv, int v, Paint.FontMetricsInt fontMetricsInt) {
}
}
}
下面是我的xml-
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:layout_gravity="center"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<EditText
android:padding="5dp"
android:background="@drawable/border"
android:id="@+id/edittext"
android:layout_centerInParent="true"
android:textColor="@android:color/black"
android:gravity="center"
android:hint="hi"
android:singleLine="false"
android:inputType="textMultiLine"
android:textSize="30sp"
android:maxWidth="100dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
下面是我使用setSpan-
这是我想要的固定宽度的正常行为-
This is normal behaviour for fixed width, that i want -
推荐答案
activity_main.xml
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/holo_purple"
tools:context="com.tttzof.demotext.MainActivity">
<EditText
android:id="@+id/editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="Enter text"
android:textSize="30sp"
android:gravity="center"
android:textColor="@android:color/black"
android:background="@android:color/transparent"
android:layout_gravity="center"/>
</FrameLayout>
MainActivity.java
MainActivity.java
import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.Spannable;
import android.text.TextWatcher;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText editText = (EditText) findViewById(R.id.editText);
int padding = dp(8);
int radius = dp(5);
final Object span = new BackgroundColorSpan(
Color.WHITE,
(float)padding,
(float) radius
);
editText.setShadowLayer(padding, 0f, 0f, 0);
editText.setPadding(padding, padding, padding, padding);
editText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void afterTextChanged(Editable s) {
s.setSpan(span, 0, s.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}
});
}
private int dp(int value) {
return (int) (getResources().getDisplayMetrics().density * value + 0.5f);
}
}
BackgroundColorSpan.java
BackgroundColorSpan.java
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.text.style.LineBackgroundSpan;
public class BackgroundColorSpan implements LineBackgroundSpan {
private float padding;
private float radius;
private RectF rect = new RectF();
private Paint paint = new Paint();
private Paint paintStroke = new Paint();
private Path path = new Path();
private float prevWidth = -1f;
private float prevLeft = -1f;
private float prevRight = -1f;
private float prevBottom = -1f;
private float prevTop = -1f;
public BackgroundColorSpan(int backgroundColor,
float padding,
float radius) {
this.padding = padding;
this.radius = radius;
paint.setColor(backgroundColor);
//paintStroke.setStyle(Paint.Style.STROKE);
//paintStroke.setStrokeWidth(5f);
paintStroke.setColor(backgroundColor);
}
@Override
public void drawBackground(
final Canvas c,
final Paint p,
final int left,
final int right,
final int top,
final int baseline,
final int bottom,
final CharSequence text,
final int start,
final int end,
final int lnum) {
float width = p.measureText(text, start, end) + 2f * padding;
float shift = (right - width) / 2f;
rect.set(shift, top, right - shift, bottom);
if (lnum == 0) {
c.drawRoundRect(rect, radius, radius, paint);
} else {
path.reset();
float dr = width - prevWidth;
float diff = -Math.signum(dr) * Math.min(2f * radius, Math.abs(dr/2f))/2f;
path.moveTo(
prevLeft, prevBottom - radius
);
path.cubicTo(
prevLeft, prevBottom - radius,
prevLeft, rect.top,
prevLeft + diff, rect.top
);
path.lineTo(
rect.left - diff, rect.top
);
path.cubicTo(
rect.left - diff, rect.top,
rect.left, rect.top,
rect.left, rect.top + radius
);
path.lineTo(
rect.left, rect.bottom - radius
);
path.cubicTo(
rect.left, rect.bottom - radius,
rect.left, rect.bottom,
rect.left + radius, rect.bottom
);
path.lineTo(
rect.right - radius, rect.bottom
);
path.cubicTo(
rect.right - radius, rect.bottom,
rect.right, rect.bottom,
rect.right, rect.bottom - radius
);
path.lineTo(
rect.right, rect.top + radius
);
path.cubicTo(
rect.right, rect.top + radius,
rect.right, rect.top,
rect.right + diff, rect.top
);
path.lineTo(
prevRight - diff, rect.top
);
path.cubicTo(
prevRight - diff, rect.top,
prevRight, rect.top,
prevRight, prevBottom - radius
);
path.cubicTo(
prevRight, prevBottom - radius,
prevRight, prevBottom,
prevRight - radius, prevBottom
);
path.lineTo(
prevLeft + radius, prevBottom
);
path.cubicTo(
prevLeft + radius, prevBottom,
prevLeft, prevBottom,
prevLeft, rect.top - radius
);
c.drawPath(path, paintStroke);
}
prevWidth = width;
prevLeft = rect.left;
prevRight = rect.right;
prevBottom = rect.bottom;
prevTop = rect.top;
}
}
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