AWT

  • When you invoke repaint() for a Component, the AWT package calls update() for the Component, which in invokes paint() in its default behavior.
  • What does the following line of code do?
TextField tf = new TextField(30);

TextField defines a constructor that takes the number of columns, as shown in the example. TextField objects can have their text updated at any time, including long after they're created.


  • Which LayoutManager arranges components left to right, then top to bottom, centering each row as it moves to the next? FlowLayout
  •  A component can be resized horizontally, but not vertically, when it is placed in which region of a BorderLayout? North and South only can resize a component horizontally, to the width of the Container
  • How can you place three Components along the bottom of a Container? Set the Container's LayoutManager to be a BorderLayout; add each Component to a different Container that uses a FlowLayout, and then add that Container to the "South" of the first Container.
  • How would you make the background color red for a Panel referenced by the variable p? "p.setBackground(Color.red);"
  • What does the following code do? drawArc(50, 40, 20, 20, 90, 180);
    • The four parameters are the left, top, width, height, start angle (0 is the 3:00 position), and the arc angle (the arc ends at start angle plus the arc angle), drawn counter-clockwise.
  • What does the following code do (if anything)? 
drawLine(0, 10, 20, 30);
The drawLine() method takes four parameters: the starting point and the ending point of the line to draw.

  • What Graphics methods will draw the outline of a square? You can use drawRect() to draw a rectangle outline given its upper left point and width and height, and drawPolygon() to draw each of the four points of the square, plus an end point that is the same as the first point.
  • What method from Java 1.0.2 can you use to remove a Component from a user interface display? The hide() method is more-or-less the opposite of show() and removes a Component from the display.
  • Returning a value of false in Java 1.0.2 from an event handler: Returning false indicates that method did not handle the event, which means AWT passes the event up the container hierarchy looking for someone who does want to handle it.
  • If you’d like to change the size of a Component, you can use the Java 1.1-specific method: setSize() is specific to Java 1.1
  • The setForeground() and setBackground() methods are defined in class: Component


    Comments

    Post a Comment

    Popular posts from this blog

    jQgrid reload with new data

    To reload a jQGrid with fresh data you need to set the data parameter on the grid and invoke reload on it. jQuery("#promotionsGrid").setGridParam({ 'data': newData}).trigger("reloadGrid"); Here newData is a JavaScript array with which I need to re-load the grid. The important thing here is that I had to place this statement just before the grid initialization code even though the reload was expected on change event of a text box. Without that there was simply no effect on my grid!
    Read more

    Introduction to jQgrid

    Introduction Why waste time in developing lists /customizing Liferay OOB search container to display data in tabular format. On top of that more often then not we end up coding for sorting of columns, pagination and formatting some data depending on their values. Trirand has come up with a jQuery plugin called jQgrid. jQgrid supports all of such ease. It provides a nice-looking grid with built-in features such as sorting, editing, search, drill-down, tree lists, and more. It is based upon jQuery and integrates well with Liferay.  The grid is dual-licensed under both the GPL and MIT licenses  (just like
    Read more

    Rich Client based UI technologies- A Comparison of Thick Client UI tools

    Rich Client v/s Thin Client Software developers face many difficult decisions when building new applications, not the least of which is graphical user interface. There are various graphical user interface technologies used, but broadly they can be classified as Rich Client User interfaces and the thin client or web based user interfaces. To understand them better let us look at the history of rich and thin clients. While the Rich client GUI applications would support high quality end-user experience with features such a drag-and-drop, perspectives, customization, high speed local processing; it has had a traditional disadvantage of high deployment and upgrade costs. It was becoming highly difficult and costly to deploy and upgrade these applications. Then came the thin clients or the Web based applications. Thin clients solved many of the deployment and upgrade problems, but that was not without a cost, the cost was in terms of functionality and capability. Thin clients, based on...
    Read more