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我正在研究一個EditText，它可以採用此question中提到的粗體，斜體和下劃線字符。我的自定義EditText工作不正常
我擴展了EditText並覆蓋了onTextChanged（）方法。 我的代碼對任何粗體，斜體，下劃線輸入的第一次出現都很好，但在第二次出現後，第一次出現變爲正常文本。
Here is a gif depecting the problem
這裏是MainActivity.java
package com.example.syed.andtexteditor;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
int helperCounterB = 0;
int helperCounterI = 0;
int helperCounterU = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button boldButton = (Button) findViewById(R.id.bold_button);
boldButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Button boldButton = (Button) findViewById(R.id.bold_button);
helperCounterB++;
if (helperCounterB % 2 != 0)
//The EditText is in Bold mode when the Bold button is pressed odd-th time
boldButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.black));
else
boldButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.grey));
TextArea t = (TextArea) findViewById(R.id.textInput);
t.applyTypeface(helperCounterI, helperCounterB, helperCounterU);
}
});
Button italicsButton = (Button) findViewById(R.id.italics_button);
italicsButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Button italicsButton = (Button) findViewById(R.id.italics_button);
helperCounterI++;
if (helperCounterI % 2 != 0) //The EditText is in Italics mode when the Italics button is pressed odd-th time
italicsButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.black));
else
italicsButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.grey));
TextArea t = (TextArea) findViewById(R.id.textInput);
t.applyTypeface(helperCounterI, helperCounterB, helperCounterU);
}
});
Button underlineButton = (Button) findViewById(R.id.underline_button);
underlineButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Button underlineButton = (Button) findViewById(R.id.underline_button);
helperCounterU++;
if (helperCounterU % 2 != 0)//The EditText is in Underline mode when the Underline button is pressed odd-th time
underlineButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.black));
else
underlineButton.setTextColor(ContextCompat.getColor(MainActivity.this, R.color.grey));
TextArea t = (TextArea) findViewById(R.id.textInput);
t.applyTypeface(helperCounterI, helperCounterB, helperCounterU);
}
});
}
}
這裏是擴展的EditText類即TextArea.java
package com.example.syed.andtexteditor;
import android.content.Context;
import android.graphics.Typeface;
import android.support.v7.widget.AppCompatEditText;
import android.text.Editable;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.TextUtils;
import android.text.style.CharacterStyle;
import android.text.style.StyleSpan;
import android.text.style.UnderlineSpan;
import android.util.AttributeSet;
import android.util.Log;
/**
* Created by Syed on 29-05-2017.
*/
public class TextArea extends AppCompatEditText {
Context c;
public static final int TYPEFACE_NORMAL = 0;
public static final int TYPEFACE_BOLD = 1;
public static final int TYPEFACE_ITALICS = 2;
public static final int TYPEFACE_BOLD_ITALICS = 3;
public static final int TYPEFACE_UNDERLINE = 4;
public static final int TYPEFACE_BOLD_UNDERLINE = 5;
public static final int TYPEFACE_ITALICS_UNDERLINE = 6;
public static final int TYPEFACE_BOLD_ITALICS_UNDERLINE = 7;
private int currentTypeface;
private int lastCursorPosition;
private StyleSpan normalspan = new StyleSpan(Typeface.NORMAL);
private StyleSpan boldspan = new StyleSpan(Typeface.BOLD);
private StyleSpan italicspan = new StyleSpan(Typeface.ITALIC);
private StyleSpan boldItalicspan = new StyleSpan(Typeface.BOLD_ITALIC);
private UnderlineSpan underlinespan = new UnderlineSpan();
public TextArea(Context context) {
super(context);
c = context;
lastCursorPosition = this.getSelectionStart();
}
public TextArea(Context context, AttributeSet attrs) {
super(context, attrs);
}
public void changeTypeface(int tfId) {
currentTypeface = tfId;
lastCursorPosition = this.getSelectionStart();
}
public void applyTypeface(int helperCounterI, int helperCounterB, int helperCounterU) {
int min = 0;
int max = this.getText().length();
if (this.isFocused()) {
final int selStart = this.getSelectionStart();
final int selEnd = this.getSelectionEnd();
min = Math.max(0, Math.min(selStart, selEnd));
max = Math.max(0, Math.max(selStart, selEnd));
}
Spannable s = this.getText();
Editable selectedText = new SpannableStringBuilder(s, min, max);
SpannableStringBuilder s1 = new SpannableStringBuilder(s, 0, min);
String selectedTextString = selectedText.toString();
SpannableStringBuilder selectedSpannedString = new SpannableStringBuilder(selectedTextString);
Log.d(VIEW_LOG_TAG, "Helper Counter I: " + helperCounterI + " Helper Counter B: " + helperCounterB);
if (helperCounterI % 2 != 0 && helperCounterB % 2 != 0 && helperCounterU % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TextArea.TYPEFACE_BOLD_ITALICS);
}
//ignore this part as there are no issues with this
else {
StyleSpan styleSpan = new StyleSpan(Typeface.BOLD_ITALIC);
selectedSpannedString.setSpan(styleSpan, min, max, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterI % 2 != 0 && helperCounterB % 2 == 0 && helperCounterU % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TextArea.TYPEFACE_ITALICS);
}
//ignore this part as there are no issues with this
else {
StyleSpan styleSpan = new StyleSpan(Typeface.ITALIC);
selectedSpannedString.setSpan(styleSpan, min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterI % 2 == 0 && helperCounterB % 2 != 0 && helperCounterU % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TextArea.TYPEFACE_BOLD);
}
//ignore this part as there are no issues with this
else {
StyleSpan styleSpan = new StyleSpan(Typeface.BOLD);
selectedSpannedString.setSpan(styleSpan, min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterB % 2 == 0 && helperCounterI % 2 == 0 && helperCounterU % 2 == 0) {
this.changeTypeface(TextArea.TYPEFACE_NORMAL);
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 == 0 && helperCounterB % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_UNDERLINE);
}
//ignore this part as there are no issues with this
else {
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 == 0 && helperCounterB % 2 != 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_BOLD_UNDERLINE);
}
//ignore this part as there are no issues with this
else {
selectedSpannedString.setSpan(new StyleSpan(Typeface.BOLD), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 != 0 && helperCounterB % 2 == 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_ITALICS_UNDERLINE);
} else
//ignore this part as there are no issues with this
{
selectedSpannedString.setSpan(new StyleSpan(Typeface.ITALIC), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
} else if (helperCounterU % 2 != 0 && helperCounterI % 2 != 0 && helperCounterB % 2 != 0) {
if (this.getSelectionEnd() == this.getSelectionStart()) {
this.changeTypeface(TYPEFACE_BOLD_ITALICS_UNDERLINE);
}
//ignore this part as there are no issues with this
else {
selectedSpannedString.setSpan(new StyleSpan(Typeface.BOLD_ITALIC), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
selectedSpannedString.setSpan(new UnderlineSpan(), min, max, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
SpannableStringBuilder s3 = new SpannableStringBuilder(s, max, s.length());
CharSequence finalSpannable = TextUtils.concat(s1, selectedSpannedString, s3);
this.setText(finalSpannable);
}
}
}
@Override
protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
Log.d(VIEW_LOG_TAG, "Start: " + start + " Length before: " + lengthBefore + " Length After: " + lengthAfter + " TextLength: " + text.length());
CharacterStyle ss = null;
UnderlineSpan ss1 = null;
int endLength = text.toString().length();
switch (currentTypeface) {
case TYPEFACE_NORMAL:
ss = normalspan;
break;
case TYPEFACE_BOLD:
ss = boldspan;
break;
case TYPEFACE_ITALICS:
ss = italicspan;
break;
case TYPEFACE_BOLD_ITALICS:
ss = boldItalicspan;
break;
case TYPEFACE_UNDERLINE:
ss = underlinespan;
break;
case TYPEFACE_BOLD_UNDERLINE:
ss = boldspan;
ss1 = underlinespan;
break;
case TYPEFACE_ITALICS_UNDERLINE:
ss = italicspan;
ss1 = underlinespan;
break;
case TYPEFACE_BOLD_ITALICS_UNDERLINE:
ss = boldItalicspan;
ss1 = underlinespan;
break;
}
if (lastCursorPosition > endLength)
return;
Log.d(TextArea.class.getSimpleName(), new Integer(lastCursorPosition).toString() + new Integer(endLength).toString());
this.getText().setSpan(ss, lastCursorPosition, endLength, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
this.getText().setSpan(ss1, lastCursorPosition, endLength, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}
}
解決了這個問題，但之前的問題重新出現了。昨天我問了這個問題https://stackoverflow.com/q/44984121/5045878，問題的解決方案是重新使用跨度。 –
當然，如果每次文本更改時重新分配每個跨度，事情會變得很慢。你的邏輯需要做的是確定你是否在跨度中，然後重新使用現有的活動。如果您正在開始一個新跨度，請爲該用例創建一個新跨度，然後重新使用它，直至完成使用。然後，當您刪除字符時，您可以重新使用不再使用的跨度。這很複雜，超出了問題的範圍。 – dominicoder
這對我來說有點超出範圍。請問這[答案]（https://stackoverflow.com/a/21972806/5045878）的工作？ –