CODEWITHSUNDEEP
javajtextfieldswingx
user3092671
user3092671

Reputation: 108

What is the width of a "column" for a JTextField?

Per the JTextField doc, you can set the width of the field delineated in “columns”, but cannot find a definition for “columns”.

Moreover, doing something like this:

new JTextField("abc", 3);

Results in a text field of width populated with the string abc and then extra whitespace afterwards.

Can someone clarify the the definition of columns as used in the JTextField constructor?

Upvotes: 3

Views: 7804

Answers (3)

BUDDHIKA
BUDDHIKA

Reputation: 316

Thanks for the Enwired's answer. This bugged me for some time. To further elaborate Enwired's answer, it is the number of m's that the JTextField can display on the screen (panel or window).

Observations

new JTextField("mmm", 3);   // this 3 is number of 'm' that we allow to fit in, please note that 'mmm' and 'abc' widths are different even though they are same character count, that is 3

For the above code it will display a JTextField with 3 m's width. (we can type more m's on this JTextField, but on the TextField it shows only 3m's)

enter image description here

If we type "abc" on this, there is still remaining space on the text field where we can accommodate another character like shown below,

enter image description here

new JTextField("mmm", 3);

so, the conclusion seems to be it (argument value 3) is not the number of characters that we can fit into JTextField, but the number of 'm' that we can fit in.

Upvotes: 0

Enwired
Enwired

Reputation: 1593

If you are using a standard JTextField, the columns specifies the preferred width of the component as some multiple of getColumnWidth().

The method getColumnWidth() defines the width in pixels of each column. The documentation states: "By default this is defined to be the width of the character 'm' for the font used."

The text field may display at a different size if the layout manager modifies it.

Upvotes: 4

g_haxor
g_haxor

Reputation: 29

The columns property of JTextField is used to determine the preferred width of the object. If an initial String is provided as in your example new JTextField("abc", 3); then the field is painted to match the text size. Otherwise, the columns allow parallel stacking of text within the JTextField itself. Therefore, the reason you get whitespace after the "abc" in your example is because it defaults to place the string in the first column, then two columns of whitespace.

Upvotes: 1

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