java – 水平滚动和TextField错误

我使用这个概念来动态地改变您的Horizo??ntalFieldManager的虚拟范围,这取决于当前需要多少空间才能适应BasicEditField中的文本.为此,我必须让Horizo??ntalFieldManager通过实现FieldChangeListener监听BasicEditField的更改.然后,当每个字符输入到编辑字段时,水平字段管理器将重新计算现在在该字段中的文本量所需的宽度.然后将虚拟宽度重新设置为该宽度.

这使得水平字段管理器只允许滚动到输入的文本的末尾,而不是右边的方式,这是代码最初工作的方式.

所以,我不认为黑莓手机做错了什么…没有操作系统的bug.以前,虚拟范围没有设置.

我将您的Horizo??ntalFieldManager拆分成一个新的私有类,因为当逻辑超过5行代码时,我不喜欢使用匿名类.所以,下面的解决方案有所不同.

其他想法：

1)由于您尝试使用自定义paint()实现绘制边框,因此存在绘图工件.但是,那个bug最初在那里,我把这个问题解释成是滚动问题.看起来您正在尝试使用Border对象,这可能是实现滚动字段边框的更好方式.

2)使用我的新解决方案,实际的CustomTextField类没有太多的内容.它只是CustomHorizo??ntalFieldManager的容器(Manager).如果你想要的话,你可能会摆脱外层.但是,我知道有时你发布代码时,会删除对您遇到麻烦的事情不重要的细节.所以,也许需要一个VerticalFieldManager包含一个Horizo??ntalFieldManager,它包含一个BasicEditField.我会把它留给你,但它只会是可选的清理.

3)我在5.0 Storm2模拟器上测试了这个.

import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.FieldChangeListener;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Manager;
import net.rim.device.api.ui.component.BasicEditField;
import net.rim.device.api.ui.container.HorizontalFieldManager;
import net.rim.device.api.ui.container.VerticalFieldManager;
import net.rim.device.api.util.Arrays;

public class CustomTextField extends VerticalFieldManager {

   private int textWidth = 0;
   private int textHeight = 0;
   private CustomHorizontalFieldManager hfm;

   public CustomTextField(int width,int height) {
      super();

      textWidth = width;
      textHeight = height;

      hfm = new CustomHorizontalFieldManager();
      add(hfm);
   }

   protected void sublayout(int maxWidth,int maxHeight) {
      super.sublayout(textWidth,textHeight);
      setExtent(textWidth,textHeight);
   }

   protected void paint(Graphics graphics) {
      // TODO: change me!
      super.paint(graphics);
      graphics.setColor(Color.BLACK);
      graphics.drawRect(0,textHeight);
   }

   private class CustomHorizontalFieldManager extends HorizontalFieldManager implements FieldChangeListener {

      private BasicEditField basicEditField;
      /** the maximum virtual width of the edit field,based on the max num of chars */
      private int maxVirtualWidth;

      public CustomHorizontalFieldManager() {
         super(Manager.HORIZONTAL_SCROLL);

         int maxNumChars = 200;
         basicEditField = new BasicEditField("",maxNumChars,BasicEditField.NO_NEWLINE);

         // determine how wide the field would need to be to hold 'maxNumChars',with the font
         //   in use ... just pick a long string of all W's,since that's usually the widest char
         char[] buffer = new char[maxNumChars];
         Arrays.fill(buffer,'W');
         String spacer = new String(buffer);
         maxVirtualWidth = basicEditField.getFont().getAdvance(spacer);

         // we need to listen as the user types in this field,so we can dynamically alter its
         //   virtual width
         basicEditField.setChangeListener(this);

         add(basicEditField);
      }

      protected void sublayout(int maxWidth,int maxHeight) {
         super.sublayout(maxWidth,maxHeight);
         // extent is the visible size,virtual extent can be wider if we want scrolling
         setExtent(textWidth,textHeight);
         setVirtualExtent(maxVirtualWidth,textHeight);
      }

      public void fieldChanged(Field f,int context) {
         if (f == basicEditField) {
            // recalculate how much virtual width the edit field needs,based on the 
            //  current text content
            int newWidth = basicEditField.getFont().getAdvance(basicEditField.getText());
            setVirtualExtent(newWidth,textHeight);
         }
      }
   }

}