ParagraphView preferrence change

Question

我有一個JTextPane，在它上面是我的Swing應用程序中的JSlider。當我拖動滑塊時，我想要JTextPane的當前有脫字符的段落減少/增加其寬度（並相應地調整高度）。我已經實現了下面的代碼，但似乎沒有任何工作。之前我已經實現了一些與此類似的功能，但我認爲我現在缺少一些東西。任何人都可以指出這個錯誤。

public class ExtendedParagraphView extends ParagraphView { 
    /** Maximum width of a single char (assuming monospaced font) {#{@value}}*/ 
    public static final float CHARACTER_WIDTH = (float) 8.0; 
    /* DELTA is used to adjust the width of the paragraph view */ 
    private float DELTA = (float) 0.0; 
    public ExtendedParagraphView(Element arg0) { 
     super(arg0); 
    } 

    /** 
    * Shift the paragraph to the left/right by an amount given by the 
    * difference between the end and the start position 
    * @param start 
    * @param end 
    */ 
    public void shiftParagraphView (int start, int end) { 
     /* The difference in pixel position is always calculated in terms of the 
     * difference between the end and start position */ 
     DELTA = (float)(end - start) * ExtendedParagraphView.CHARACTER_WIDTH; 
    } 

    @Override 
    public float getPreferredSpan (int axis) { 
     if (axis == View.Y_AXIS) { 
      return super.getPreferredSpan(axis); 
     } 
     return super.getPreferredSpan(axis) - this.DELTA; 
    } 
} 

以下是ExtendedParagraphView內部的shiftParagraphView方法調用時的代碼。

protected void shiftTextPaneElement (int start, int end) { 
    if (start == end) { 
     return; 
    } 

    int dot = this.textpane.getCaret().getDot(); 
    int mark = this.textpane.getCaret().getMark(); 
    int pos = mark <= dot ? mark : dot; 

    View view = textpane.getUI().getRootView(textpane); 
    int n = view.getViewCount(); 
    for (int i = 0; i < n; i++) { 
     View v = view.getView(i); 
     if (v instanceof BoxView) { 
      int m = v.getViewCount(); 
      for (int k = 0; k < m; k++) { 
       View vv = v.getView(k); 
       if (vv instanceof ExtendedParagraphView) { 
        ((ExtendedParagraphView) vv). 
         shiftParagraphView(start, end); 
        return; //only a single paragraph is currently shifted 
       } 
      } 
     } 
    } 
} 

注：經過一些試驗和錯誤以下似乎是工作，

public void shiftParagraphView (int start, int end) { 
    DELTA = (float)(end - start) * ExtendedParagraphView.CHARACTER_WIDTH; 
    this.setInsets(getTopInset(), (short) (getLeftInset() + DELTA), 
     getBottomInset(), getRightInset()); 
    this.getParent().preferenceChanged(this, true, false); 
    this.getContainer().repaint(); 
} 

Answer 1

使用yourStyledDocument.setParagraphAttributes()而不是指定所需的左，右縮進。