Flex 4 Tree Lines

I've updated my previous blog post on Tree Lines to include a Flex 4/Spark version which uses the MXTreeItemRenderer class.

For more documentation on how to use it see the blog post linked above.


I've also updated the AdvancedDataGrid example to show tree lines in the tree:

Tree Item ToolTips

Here is how you can set custom tooltips in Flex 3 on each item in a Tree.

First, you have to set the following properties on the Tree:

• showDataTips="true" - causes tooltips to be shown
• dataTipFunction="myDataTipFunction" - sets the function which returns the tooltip for each item
• itemRenderer="ToolTipItemRenderer" - tells the tree to use our custom renderer (which extends the default TreeItemRenderer)

The itemRenderer isn't necessary unless you want to have control over where the tooltip is positioned (see below).

Also note that if you set the dataTipField property on the tree instead of the dataTipFunction then your tooltips will only show up when the tree item isn't fully visible due to scrollbars. By setting the dataTipFunction it forces the tooltips to always show when the mouse is over the tree node.

Now, on to the next problem. By using the method above the tooltips are always displayed. But the default position for the tooltip is right on top of the tree node, which is annoying. So this is why we use our own custom item renderer so that we can position the tooltip below or above the node (or anywhere you want it).

Here is an example with View Source enabled:

Tree Lines

In Flex I've seen how you can configure Trees by changing the disclosure (expand/collapse) icon, the folder/leaf icons, background colors, indentation, etc. But I've never seen the option for rendering tree lines like you can in Java, C# and most other languages.

I've created a custom TreeItemRenderer that does renderer tree lines. It has these properties:

<ui:TreeItemLinesRenderer
Styles
lineAlpha="1"
lineColor="#808080"
lineThickness="1"
lineStyle="dotted"/>

And here is an example of it in action (right click to view source):


If you know of any other solutions out there I'd be interested to see them.

** September 28th 2009 Updated **
I've added another example application showing how to render tree lines in an AdvancedDataGrid control.

Flex Example Application

AdvancedDataGrid API

AdvancedDataGridGroupItemRenderer API

Flex 4/Spark Version
Here is a very similar version written in Flex 4. It uses a lot of the same code, but uses a Spark item renderer instead. There is probably a much nicer way to do this using the new Spark Path or Line controls, but since the code was already written I went with this solution.

An example of tree lines in an AdvancedDataGrid with a Flex 4 itemRenderer is on my newer blog post.

Tree Icon Spinner (not using animated gif)

I've been disappointed that Flex doesn't natively support animated gifs. I especially wanted to use them inside Flex Trees when I'm loading the children dynamically. So instead of trying to get animated gifs to work (see this example if you are interested) I created a relatively simple Spinner class that draws a circular spinner using just Flex Graphics. The spinner is animated using a Timer. If you set the startImmediately property to true then the animation starts when the spinner component is added to a parent component. And it is always stopped when it gets removed from its parent.
There are also the start(), stop() and running functions to control the spinner manually.

The spinners have a few styles that you can set to customize the appearance:

<ui:Spinner
  Properties
delay="100"
startImmediately="false"
Styles
backgroundAlpha="1"
backgroundColor="NaN"
spinnerColor="#829AD1"
spinnerHighlightColor="#001A8E"
spinnerThickness="3"
spinnerLineThickness="2"
spinnerType="gradientcircle"/>

I've created an example of the four types of spinners in four Trees. Each tree node loads its children after a 2 second delay during which time the spinner is shown, so try expanding each tree (right click to view source):


Let me know if you like them!

Also, make sure you do call stop() on the spinner when you don't need it anymore... otherwise you might notice your Flex app starts to run very slowly like mine did...

** September 28th 2009 Updated **
I've added another example application showing how to show the spinner inside an AdvancedDataGrid control.

Flex Example Application

AdvancedDataGrid API

AdvancedDataGridGroupItemRenderer API