Package org.eclipse.swt.custom

Class CLabel

java.lang.Object
org.eclipse.swt.widgets.Widget
org.eclipse.swt.widgets.Control
org.eclipse.swt.widgets.Scrollable
org.eclipse.swt.widgets.Composite
org.eclipse.swt.widgets.Canvas
org.eclipse.swt.custom.CLabel
All Implemented Interfaces:
Adaptable, Drawable
public class CLabel extends Canvas
A Label which supports aligned text and/or an image and different border styles.

If there is not enough space a CLabel uses the following strategy to fit the information into the available space: 

                ignores the indent in left align mode
                ignores the image and the gap
                shortens the text by replacing the center portion of the label with an ellipsis
                shortens the text by removing the center portion of the label

Styles:
LEFT, RIGHT, CENTER, SHADOW_IN, SHADOW_OUT, SHADOW_NONE
Events:

IMPORTANT: This class is not intended to be subclassed.

Since:
1.0

  • Constructor Details

    • CLabel

      public CLabel(Composite parent, int style)
      Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

      The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

      Parameters:
      parent - a widget which will be the parent of the new instance (cannot be null)
      style - the style of widget to construct
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the parent is null
      SWTException -
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
      See Also:

  • Method Details

    • computeSize

      public Point computeSize(int wHint, int hHint, boolean changed)
      Description copied from class: Control
      Returns the preferred size of the receiver.

      The preferred size of a control is the size that it would best be displayed at. The width hint and height hint arguments allow the caller to ask a control questions such as "Given a particular width, how high does the control need to be to show all of the contents?" To indicate that the caller does not wish to constrain a particular dimension, the constant SWT.DEFAULT is passed for the hint.

      If the changed flag is true, it indicates that the receiver's contents have changed, therefore any caches that a layout manager containing the control may have been keeping need to be flushed. When the control is resized, the changed flag will be false, so layout manager caches can be retained.

      Overrides:
      computeSize in class Composite
      Parameters:
      wHint - the width hint (can be SWT.DEFAULT)
      hHint - the height hint (can be SWT.DEFAULT)
      changed - true if the control's contents have changed, and false otherwise
      Returns:
      the preferred size of the control.
      See Also:

    • getAlignment

      public int getAlignment()
      Returns the alignment. The alignment style (LEFT, CENTER or RIGHT) is returned.
      Returns:
      SWT.LEFT, SWT.RIGHT or SWT.CENTER

    • getImage

      public Image getImage()
      Return the CLabel's image or null.
      Returns:
      the image of the label or null

    • getStyle

      public int getStyle()
      Description copied from class: Widget
      Returns the receiver's style information.

      Note that the value which is returned by this method may not match the value which was provided to the constructor when the receiver was created. This can occur when the underlying operating system does not support a particular combination of requested styles. For example, if the platform widget used to implement a particular SWT widget always has scroll bars, the result of calling this method would always have the SWT.H_SCROLL and SWT.V_SCROLL bits set.

      Overrides:
      getStyle in class Widget
      Returns:
      the style bits

    • getText

      public String getText()
      Return the Label's text.
      Returns:
      the text of the label or null

    • getToolTipText

      public String getToolTipText()
      Description copied from class: Control
      Returns the receiver's tool tip text, or null if it has not been set.
      Overrides:
      getToolTipText in class Control
      Returns:
      the receiver's tool tip text

    • setAlignment

      public void setAlignment(int align)
      Set the alignment of the CLabel. Use the values LEFT, CENTER and RIGHT to align image and text within the available space.
      Parameters:
      align - the alignment style of LEFT, RIGHT or CENTER
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • ERROR_INVALID_ARGUMENT - if the value of align is not one of SWT.LEFT, SWT.RIGHT or SWT.CENTER

    • setBackground

      public void setBackground(Color color)
      Description copied from class: Control
      Sets the receiver's background color to the color specified by the argument, or to the default system color for the control if the argument is null.
      Overrides:
      setBackground in class Control
      Parameters:
      color - the new color (or null)

    • setBackground

      public void setBackground(Image image)
      Set the image to be drawn in the background of the label.
      Parameters:
      image - the image to be drawn in the background
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

    • setBackground

      public void setBackground(Color[] colors, int[] percents)
      Specify a gradient of colours to be drawn in the background of the CLabel.

      For example, to draw a gradient that varies from dark blue to blue and then to white and stays white for the right half of the label, use the following call to setBackground:

        clabel.setBackground(new Color[]{display.getSystemColor(SWT.COLOR_DARK_BLUE),
                               display.getSystemColor(SWT.COLOR_BLUE),
                               display.getSystemColor(SWT.COLOR_WHITE),
                               display.getSystemColor(SWT.COLOR_WHITE)},
                   new int[] {25, 50, 100});
      Parameters:
      colors - an array of Color that specifies the colors to appear in the gradient in order of appearance from left to right; The value null clears the background gradient; the value null can be used inside the array of Color to specify the background color.
      percents - an array of integers between 0 and 100 specifying the percent of the width of the widget at which the color should change; the size of the percents array must be one less than the size of the colors array.
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • ERROR_INVALID_ARGUMENT - if the values of colors and percents are not consistent
      Since:
      1.4

    • setBackground

      public void setBackground(Color[] colors, int[] percents, boolean vertical)
      Specify a gradient of colours to be drawn in the background of the CLabel.

      For example, to draw a gradient that varies from dark blue to white in the vertical, direction use the following call to setBackground:

        clabel.setBackground(new Color[]{display.getSystemColor(SWT.COLOR_DARK_BLUE),
                               display.getSystemColor(SWT.COLOR_WHITE)},
                     new int[] {100}, true);
      Parameters:
      colors - an array of Color that specifies the colors to appear in the gradient in order of appearance from left/top to right/bottom; The value null clears the background gradient; the value null can be used inside the array of Color to specify the background color.
      percents - an array of integers between 0 and 100 specifying the percent of the width/height of the widget at which the color should change; the size of the percents array must be one less than the size of the colors array.
      vertical - indicate the direction of the gradient. True is vertical and false is horizontal.
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • ERROR_INVALID_ARGUMENT - if the values of colors and percents are not consistent
      Since:
      1.4

    • setFont

      public void setFont(Font font)
      Description copied from class: Control
      Sets the font that the receiver will use to paint textual information to the font specified by the argument, or to the default font for that kind of control if the argument is null.
      Overrides:
      setFont in class Control
      Parameters:
      font - the new font (or null)

    • setImage

      public void setImage(Image image)
      Set the label's Image. The value null clears it.
      Parameters:
      image - the image to be displayed in the label or null
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

    • setText

      public void setText(String text)
      Set the label's text. The value null clears it.
      Parameters:
      text - the text to be displayed in the label or null
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

    • setToolTipText

      public void setToolTipText(String string)
      Description copied from class: Control
      Sets the receiver's tool tip text to the argument, which may be null indicating that no tool tip text should be shown.
      Overrides:
      setToolTipText in class Control
      Parameters:
      string - the new tool tip text (or null)

    • setMargins

      public void setMargins(int leftMargin, int topMargin, int rightMargin, int bottomMargin)
      Set the label's margins, in pixels.
      Parameters:
      leftMargin - the left margin.
      topMargin - the top margin.
      rightMargin - the right margin.
      bottomMargin - the bottom margin.
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      1.3

    • setLeftMargin

      public void setLeftMargin(int leftMargin)
      Set the label's horizontal left margin, in pixels.
      Parameters:
      leftMargin - the left margin of the label, which must be equal to or greater than zero
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      1.3

    • getLeftMargin

      public int getLeftMargin()
      Return the CLabel's left margin.
      Returns:
      the left margin of the label
      Since:
      1.3

    • setTopMargin

      public void setTopMargin(int topMargin)
      Set the label's top margin, in pixels.
      Parameters:
      topMargin - the top margin of the label, which must be equal to or greater than zero
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      1.3

    • getTopMargin

      public int getTopMargin()
      Return the CLabel's top margin.
      Returns:
      the top margin of the label
      Since:
      1.3

    • setRightMargin

      public void setRightMargin(int rightMargin)
      Set the label's right margin, in pixels.
      Parameters:
      rightMargin - the right margin of the label, which must be equal to or greater than zero
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      1.3

    • getRightMargin

      public int getRightMargin()
      Return the CLabel's right margin.
      Returns:
      the right margin of the label
      Since:
      1.3

    • setBottomMargin

      public void setBottomMargin(int bottomMargin)
      Set the label's bottom margin, in pixels.
      Parameters:
      bottomMargin - the bottom margin of the label, which must be equal to or greater than zero
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      1.3

    • getBottomMargin

      public int getBottomMargin()
      Return the CLabel's bottom margin.
      Returns:
      the bottom margin of the label
      Since:
      1.3

    • setData

      public void setData(String key, Object value)
      Description copied from class: Widget
      Sets the application defined property of the receiver with the specified name to the given value.

      Applications may associate arbitrary objects with the receiver in this fashion. If the objects stored in the properties need to be notified when the widget is disposed of, it is the application's responsibility to hook the Dispose event on the widget and do so.

      Overrides:
      setData in class Control
      Parameters:
      key - the name of the property
      value - the new value for the property
      See Also:

    • getAdapter

      public <T> T getAdapter(Class<T> adapter)
      Description copied from class: Widget
      Implementation of the Adaptable interface.

      IMPORTANT: This method is not part of the RWT public API. It is marked public only so that it can be shared within the packages provided by RWT. It should never be accessed from application code.

      Specified by:
      getAdapter in interface Adaptable
      Overrides:
      getAdapter in class Canvas
      Parameters:
      adapter - the lookup class
      Returns:
      an object that can be cast to the given class or null if there is no adapter associated with the given class.