This function is used for extending the object to the gridsize, and it is very useful when your Windows is resizable. There are 3 ways to use "fill": gbc. The method is like this: import java. Component; import java. Be sure to assign a short name to GridBagConstraints, as you will deal with this variable quite a lot.
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Everything You Need To Know! May 20, by Krishna Srinivasan Leave a Comment Gridbaglayout is a popular layout manager associated with the Java programming language. But what is a layout manager, and why is using one so important to Java? A layout manager is valuable because it allows the programmer to place elements of a user interface without having to rely on pixels as a standard of measurement.
Instead, the programmer can use relative units, which is a more intuitive way of working. These programming tools aid in simplifying and involve less mathematical calculations. Gridbaglayout actually works by dividing each object programmed in Java into a dynamic, rectangular grid of cells, according to Oracle. When programmers are using Gridbaglayout, they are actually deciding which cells the layout manager uses in order to determine object placement, shape and size.
Girdbaglayout is also a dynamic layout manager, which means that it is able to react if programmed correctly to different screen sizes and resize objects accordingly. Attempting to hard code this flexibility into a program without a layout manager can cost quite a bit of time, along with creating a lot of stress for a programmer!
Quite simply, Gridbaglayout is complex. Study is necessary in order to understand and use Gridbaglayout efficently, and there is a notable learning curve. An object that uses Gridbaglayout must be assigned certain properties, which are known as Gridbagconstraints.
These properties contain much of the information assigned to the object by the programmer. The assignment of these properties is often done in a separate file, which is then loaded by the program when running. While there are many Gridbagconstraint properties or components , a number of them will be listed here as examples. A reminder to all programmers — these properties must be created first and then assigned, like all variables in a static language such as Java.
This list is not meant to be inclusive, and there will be many Gridbaglayout properties not included here. If you need more information, the University of Hamburg has an excellent web page. Gridx and Gridy The first and most obvious properties covered will be gridx and gridy. While perhaps obvious to some, these two properties determine where the object appears within the program.
These values by default are relative! This is a huge advantage for a programmer using this layout manager, because it means that an object placed using these properties will move about as the screen size is changed.
Gridx and gridy can also be set to absolute, which is less flexible, but is also more predictable — the program will not determine placement of the object using screen size, etc. Gridwidth and Gridheight Gridwidth and gridheight are two properties that behave in a similar manner. Gridwidth determines the width of an object by the number of cells that it occupies.
The default value is one, but an object may occupy as many cells as the programmer desires. The cells are occupied by row when using gridwidth. Gridheight also uses this principle, so if the programmer wishes to have a taller object than the default, then the value listed for gridheight must be greater than one. As with gridwidth, the value of one is the default value.
Gridheight occupies cells by column instead of by row. Neither of these properties use pixels or other static units of measurement. For example, the programmer has created a UI with a box that is meant to be a certain size.
However, the end user views the program on a monitor which is larger than the programmer originally designed for, and the programmer used a static method of measurement, such as pixels. The fill property can be used in this instance to dictate what the computer should do with the added space.
Valid values for the fill property include NONE, which is the default value if nothing else is assigned. This means that gridbaglayout does nothing when an object is given extra space. Ipadx and Ipady Properties The properties ipadx and ipady can be misleading. These two properties have nothing to do with a certain tablet manufactured by a well-known computer company. Instead, this property deals with internal padding. An obvious example of internal padding would be an object such as a box.
The ipadx property enables this feature horizontally, while the ipady feature enables it vertically. This default value of these properties is zero. Unlike the other properties listed so far, these properties use pixels, which are an absolute measurement to increase the size of the object.
Also note that these properties apply to both sides of the object, so the number assigned to the property should be multiplied by two in order to account for this. Of course, this also applies to the ipady property. Inset Property The inset property is rarely used, but it has so much in common with the ipadx and ipady properties that it should be covered here.
While ipadx and ipady properties deal with interior padding, the inset property deals with exterior padding. If, for example, a programmer wanted one object to remain 15 pixels away from another object, no matter what the screen configuration may be, the inset property would be used.
These two properties determine HOW content is distributed within an object. For example, if the object a programmer is building happens to be a button with a text label explaining its function, weightx and weighty will determine how the lettering is spaced. If the values of both are set to zero, which is the default, the text will clump around the center.
However, if the value of weightx is set to a number between zero and one for example. Note that, unlike the other properties covered in this article, the weight properties have their own set of values, which is not based on pixels or the grid of cells used by other properties of gridbaglayout. As with other properties used in gridbaglayout, the weightx property affects the horizontal placement of material within the object while the weighty property affects the vertical placement of material within the object.
Both properties should only contain a value between zero and one—large numbers should be avoided. As can be seen from the previous paragraphs, this article barely begins to cover all of the information necessary in order to understand gridbaglayout. However, the examples shown above should illustrate just how flexible and powerful a toolset this layout manager is. With gridbaglayout, a programmer can focus on the functionality of his Java programming, as opposed to dealing with the tedium of designing a layout for multiple viewport screens.
There is no doubt that gridbaglayout has a steep learning curve. But, for the persistent student, the boosts to productivity gained by learning it are impressive. Related posts:.
How To Use GridBaglayout In Java? Everything You Need To Know!
Unless you specify a weight for at least one component in a row weightx and column weighty , all the components clump together in the center of their container. This is because when the weight is zero the default , the GridBagLayout object puts any extra space between its grid of cells and the edges of the container. If none of the components in the row has a valid baseline, the row does not have a baseline. The row that the component is aligned to is called the prevailing row. The following figure shows a baseline layout and includes a component that spans rows: This layout consists of three components: A panel that starts in row 0 and ends in row 1.
If you are not interested in learning all the details of layout management, you might prefer to use the GroupLayout layout manager combined with a builder tool to lay out your GUI. Otherwise, if you want to code by hand and do not want to use GroupLayout, then GridBagLayout is recommended as the next most flexible and powerful layout manager. Here is a picture of an example that uses GridBagLayout. Alternatively, to compile and run the example yourself, consult the example index. A GridBagLayout places components in a grid of rows and columns, allowing specified components to span multiple rows or columns. Not all rows necessarily have the same height.
SWING - GridBagLayout Class