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This section introduce the usage of ZK auto sizing APIs. All of these can apply to following components :

Hflex and Width

There are basically two approaches to control the width of a column: width and hflex. They could be specified in the column's header, such as column and listheader. ).

While width (HtmlBasedComponent.setWidth(String)) specifies the width in precise number (such as width="100px"), hflex (HtmlBasedComponent.setHflex(String)) specifies the proportional width (such as hflex="1") or the minimal width (such as hflex="min").

Span

If the total width of all columns is smaller than the grid, there will be some whitespace shown at the right side of the grid.

If you prefer to make each column's width a bit wider to cover the whole grid, you could specify span="true" in grid/listbox/tree (such as Grid.setSpan(String)). If you want to make a particular column larger to cover the whole grid, you could specify a number, such as span="2" to expand the third column.

sizedByContent

If you want to make each column as minimal as possible, you could specify hflex="min" for each column. Alternatively, you could specify sizedByContent="true" in the grid/listbox/tree (Grid.setSizedByContent(boolean)). In other words, it implies the width of a column that is not assigned with width and hflex shall be minimal.

In general, you will specify span="true" too to cover the whole grid/listbox/tree.

Use Cases

Here we take listbox with listheaders as an example to show some different use cases.

Data Length : Short

<zk>
 	<zscript><![CDATA[
 	String[] msgs2 = {
  			"Application Developer's Perspective",
  			"Server+client Fusion architecture",
  			"Component Developer's Perspective",
  			"Execution Flow of Loading a Page",
 			"Execution Flow of Serving an Ajax Request",
  			"When to Send an Ajax Request"  	
 	};
 	]]></zscript>
	<listbox width="800px">
 		<listhead>
 			<listheader label="Product" />
 			<listheader label="Description" />
 			<listheader label="Comment" />
 		</listhead>
 		<listitem>
			<listcell><label value="${msgs2[0]}"></label></listcell>
 			<listcell><label value="${msgs2[1]}"></label></listcell>
 			<listcell><label value="${msgs2[2]}"></label></listcell>
 		</listitem>
 		<listitem>
 			<listcell><label value="${msgs2[3]}"></label></listcell>
 			<listcell><label value="${msgs2[4]}"></label></listcell>
 			<listcell><label value="${msgs2[5]}"></label></listcell>
 		</listitem>
	</listbox>
</zk>
  • Default : Data component will show the data correctly, with no width specification. (the exactly width of columns are rendered by browser automatically)

ZK5DevRef GridColumn Default.png

Proportional Width

Sure you can use the hflex we have mentioned in previous section.

	<listhead>
 			<listheader label="Product" hflex="1"/>
 			<listheader label="Description" hflex="2"/>
 			<listheader label="Comment" hflex="1" />
 	</listhead>

ZK5DevRef GridColumn hflex.png

Minimum Flexibility

In the case of hflex=min, column's width will be just fitted the contents. As you can see, there might be blank space on the right of the listbox.

        <zscript><![CDATA[
 	String[] msgs2 = {
  			"Application Developer's Perspective",
  			"Very Short Text",
 			"Server+client Fusion architecture",
 			"Execution Flow of Serving an Ajax Request",
 			"Very Short Text",
 			"When to Send an Ajax Request (Addition Text )"
  	};
        ]]></zscript>
    <listbox width="800px">
	<listhead>
 			<listheader label="Product" hflex="min"/>
 			<listheader label="Description" hflex="min"/>
 			<listheader label="Comment" hflex="min" />
 	</listhead>

ZK5DevRef GridColumn nospan.png


  • If you want your contents fill the whole grid to eliminate the blank space, you can set span=true to make it proportionally expanded.
    <listbox width="800px" span="true">
	<listhead>
 			<listheader label="Product" hflex="min"/>
 			<listheader label="Description" hflex="min"/>
 			<listheader label="Comment" hflex="min" />
 	</listhead>

ZK5DevRef GridColumn span.png


  • If you want the rest of space to be assigned to one of the columns, set span to a number. The number is 0-based index of columns.
    <listbox width="800px" span="0">
	<listhead>
 			<listheader label="Product" hflex="min" />
 			<listheader label="Description" hflex="min" />
 			<listheader label="Comment" hflex="min" />
 	</listhead>

ZK5DevRef GridColumn span0.png


  • If you want the size of the Listbox determined by it content, assign hflex=min on the Grid, and make sure all the Listheaders either have hflex=min or has a fixed width.
    <listbox hflex='min'>
	<listhead>
 			<listheader label="Product" hflex="min" />
 			<listheader label="Description" hflex="min" />
 			<listheader label="Comment" hflex="min" />
 	</listhead>

ZK5DevRef GridColumn sizedByCnt.png

Data Length : Long

        <zscript><![CDATA[
        String[] msgs2 = {
  			"Application Developer's Perspective", 
			"Very Long Long Long Long Long Long Long Long Long Long Text",
 			"Server+client Fusion architecture",
 			"Execution Flow of Serving an Ajax Request",
 			"Very Long Long Long Long Long Long Long Long Long Long Text",
 			"When to Send an Ajax Request" 
        };
        ]]></zscript>
  • Default : ZK data component will wrap the text to fit the width of column.

ZK5DevRef GridColumn DefaultLong.png

Scrollbar

When the sum of content width is larger than Grid width. The scroll appears if and only if

  1. The Columns and Column component are presented.
  2. Each of the Column components is given an as hflex or width value.


Specify Width

This is simple way to avoid text wrapped by given proper width. However, it can be difficult if you don't know the content length beforehand.

	<listhead>
 			<listheader label="Product" width="250px"/>
 			<listheader label="Description" width="470px"/>
 			<listheader label="Comment" width="280px" />
 	</listhead>

ZK5DevRef GridColumn DefaultWidth.png

Minimum Flexibility

  • Set hflex=min and ZK will calculate the length of content and set proper width to the column accordingly.
  • Notes: Remember to set every column with hflex=min or specify a specific width; otherwise those columns without setting minimum hflex or specifying a width could disappear if not enough space in the listbox.
 	<listhead>
  			<listheader label="Product" hflex="min" />
  			<listheader label="Description" hflex="min" />
  			<listheader label="Comment" hflex="min" />
  	</listhead>

ZK5DevRef GridColumn LongHflex.png

Mixed Flexibility and width

Width + Hflex proportion

 	<listhead>
  			<listheader label="Product" width="120px" />
  			<listheader label="Description" hflex="2" />
  			<listheader label="Comment" hflex="1" />
  	</listhead>

ZK5DevRef GridColumn MixhflexnumWidth.png

Width + Hflex min

 	<listhead>
  			<listheader label="Product" width="150px" />
  			<listheader label="Description" hflex="min" />
  			<listheader label="Comment" hflex="min" />
  	</listhead>

ZK5DevRef GridColumn MixhflexMinWidth.png

Width + Hflex min + Hflex proportion

 	<listhead>
  			<listheader label="Product" width="120px" />
  			<listheader label="Description" hflex="min" />
  			<listheader label="Comment" hflex="1" />
  	</listhead>

ZK5DevRef GridColumn MixhflAllh.png

Data Length : Dynamic

If users can't control the data size, that means, you should take both the short data and the long data situation into consideration.

Now we have several attributes, rules, and situations, please choose the right solution for your case.


  • (Blank) : Doesn't matter
  • V : Must set
  • X : Must not set
  • ! : Acceptable but something need notice.
Specification Span=true Hflex proportion Hflex=min Specific Width
Fill whole Grid One of below attribute was set X  !
No Scrollbar Grid V X  !
No Content Wrapping Column V  !
Fill whole Grid + No Scrollbar Grid V X  !
Fill whole Grid + No Content Wrapping V All Column Component Should have one of these attributes
  •  ! : Specific width must not more than grid's width.

Version History

Last Update : 2015/6/8


Version Date Content
5.0.6 February 2011 New specification of hflex and span.



Copyright © Potix Corporation. This article is licensed under GNU Free Documentation License.



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