com.bytezone.dm3270.attributes.StartFieldAttribute Maven / Gradle / Ivy

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This is a trimmed down version of https://github.com/dmolony/dm3270 to be used as TN3270 client library
There is a newer version: 0.15-lib
package com.bytezone.dm3270.attributes;

import com.bytezone.dm3270.display.ScreenContext;
import java.awt.Color;

public class StartFieldAttribute extends Attribute {

  private static final Color WHITE = ColorAttribute.COLORS[0];
  private static final Color BLUE = ColorAttribute.COLORS[1];
  private static final Color RED = ColorAttribute.COLORS[2];
  private static final Color GREEN = ColorAttribute.COLORS[4];
  private static final Color BLACK = ColorAttribute.COLORS[8];

  private final boolean isProtected;      // bit 2
  private final boolean isNumeric;        // bit 3
  private final boolean isModified;       // bit 7

  private boolean isExtended;         // created by StartFieldExtendedOrder
  private boolean userModified;       // used to avoid altering the original bit 7

  // these three fields are stored in two bits (4&5)
  private final boolean isHidden;
  private final boolean isHighIntensity;
  private final boolean selectorPenDetectable;

  public StartFieldAttribute(byte b) {
    super(AttributeType.START_FIELD, Attribute.XA_START_FIELD, b);

    isProtected = (b & 0x20) > 0;
    isNumeric = (b & 0x10) > 0;
    isModified = (b & 0x01) > 0;

    int display = (b & 0x0C) >> 2;
    selectorPenDetectable = display == 1 || display == 2;
    isHidden = display == 3;
    isHighIntensity = display == 2;
  }

  public void setExtended() {
    isExtended = true;
  }

  public boolean isExtended() {
    return isExtended;
  }

  public boolean isProtected() {
    return isProtected;
  }

  public boolean isHidden() {
    return isHidden;
  }

  public boolean isVisible() {
    return !isHidden;
  }

  public boolean isModified() {
    return isModified || userModified;
  }

  public void setModified(boolean modified) {
    userModified = modified;
  }

  /*
   * http://www-01.ibm.com/support/knowledgecenter/SSGMGV_3.1.0/com.ibm.cics.
   * ts31.doc/dfhp3/dfhp3at.htm%23dfhp3at
   *
   * Some terminals support base color without, or in addition to, the extended
   * colors included in the extended attributes. There is a mode switch on the
   * front of such a terminal, allowing the operator to select base or default
   * color. Default color shows characters in green unless field attributes specify
   * bright intensity, in which case they are white. In base color mode, the
   * protection and intensity bits are used in combination to select among four
   * colors: normally white, red, blue, and green; the protection bits retain their
   * protection functions as well as determining color. (If you use extended color,
   * rather than base color, for 3270 terminals, note that you cannot specify
   * "white" as a color. You need to specify "neutral", which is displayed as white
   * on a terminal.)
   */
  @Override
  public ScreenContext process(ScreenContext unused1, ScreenContext unused2) {
    assert unused1 == null && unused2 == null;

    Color color = isHighIntensity ? isProtected ? WHITE : RED : isProtected ? BLUE : GREEN;

    return new ScreenContext(color, BLACK, (byte) 0, isHighIntensity, false);
  }

  private String getColorName() {
    return isHighIntensity ? isProtected ? "WH" : "RE" : isProtected ? "BL" : "GR";
  }

  public String getAcronym() {
    return (isProtected ? "P" : "p")
        + (isNumeric ? "a" : "A")
        + (isHidden ? "v" : "V")
        + (isHighIntensity ? "I" : "i")
        + (selectorPenDetectable ? "D" : "d")
        + (isModified() ? "M" : "m");
  }

  @Override
  public String toString() {
    return String.format("Attribute %s : %02X %s", getColorName(), attributeValue,
        getAcronym());
  }

}