Develop Reference

Expandable grid Vaadin UI

I have a simple grid. Two columns with a variable amount of rows. I want to make it so i have a header row with an arrow that can collapse and show the whole grid. So when I bring up the app, only the header row is visible with an arrow, and I can click to expand/collapse to show the rest of the grid.
A TreeGrid seems like overkill since I don’t need any hierarchical structure, just the ability to collapse/expand one row. I exclusively use IE and I’ve read that Drawyer doesnt work with IE 8 and above. I return a list of the objects and the object just has two string variables.
Any help with this? I am new to Vaadin 8.

Set grid height (workaround)
As a workaround, you could set the height to be approximately the number of pixels you expect to be the height of the header.
See the Sampler demo. Click the gear icon at top to expose properties of the example Grid object. The last property shown is "Size (W x H)". Change 100% to 100px to see the effect.
Grid height set to 100%
Grid height set to 100px
You can also hide the footer (see checkbox in that property list).

I don't think this can be done with plain Vaadin. But I recommend the following simpler approach:
Initially call grid.setHeightByRows(1.5) (javadoc). This will show exactly one row and a half to indicate more data is available. A scrollbar will appear, too.
Make a new column within the grid that has a button or add a button below the grid that - when clicked - calls setHeightByRows with the number of elements in the grid and hides the button. This will show all rows.

Java JFreeChart: customize tooltip screen position

I implemented my own JFreeChart XYToolTipGenerator and, as the chart it is used on is almost full screen, sometimes the tooltip position (on screen) hides the point it is related to (e.g. in the bottom right corner, since it seems that tooltip is configured to be positioned South-East of the mouse / data point). This is a problem because the user needs to be able to click on the chart's data points (as it generates a specific action).
Is there a way to either define dynamically the position of the tooltip (e.g. for data points bottom right I would ask the tooltip to be shown North-West) or, alternatively, to define a systematic position (e.g. North-West instead of South-East as it is by default)?
This problem has given me headaches for the last few days - any help or hint is more than welcome.
Many thanks!
Thomas

Here's the answer I posted on the JFreeChart forum:
JFreeChart is using the standard Swing tool tip mechanism. In the ChartPanel class, the getToolTipText(mouseEvent) method is overridden to return the appropriate text for the tooltip, and that's it.
Swing also gives you the option to override the getToolTipLocation(mouseEvent) method, and that's probably what you need here.

Remove an axis from JavaFX Chart

I've created a XYChart with numerical values different (for example temperatue with pressure) so I want to draw my own axeS just beside my chart. To do the following I've to unshow the YAxis, how should I do that ?

By using a trick: The Chart needs the Y Axis to remain in place so it knows where to render your content. You can, however, hide it. Hide the tick labels and set the axis' opacity to 0 using this code:
chart.getYAxis().setTickLabelsVisible(false);
chart.getYAxis().setOpacity(0);
The axis will still be there, but not shown.

I found that if I hid the chart using the following code:
chart.getXAxis().setTickLabelsVisible(false);
chart.getXAxis().setTickMarkVisible(false);
((Path)chart.getXAxis().lookup(".axis-minor-tick-mark")).setVisible(false);
Then I get about ~10 pixels less blank space on the bottom. IF the space was an issue for your application then you could use css offsets to correct it. This solution may have more predictable offsets.

SOLVED: I got this to work for sharing a common x-axis for two charts stacked vertically:
Create two charts, each with their own identical copy of the x-axis object, setting identical upper and lower bounds (optionally by binding).
Then hide the x-axis in the second chart like this:
chart = new LineChart<Number,Number>(xaxis2,yaxis2) {
{// hide xAxis in constructor, since not public
getChartChildren().remove(getXAxis());
// not getPlotChildren()
}
};
You'll want to set the widths of your y-axes to be the identical, e.g.
int w = 60;
yaxis.setMaxWidth(w);
yaxis.setMinWidth(w);
yaxis.setPrefWidth(w);
yaxis2.setMaxWidth(w);
yaxis2.setMinWidth(w);
yaxis2.setPrefWidth(w);

JFreeChart - Axis label positioning

I want the label of one of my axis to be two words, each aligned to the beginning and end of said axis - I've been doing this by inserting spaces in the Axis label, but it's a crappy solution.
Is there a way to align label text for a JFreeChart chart?
Thanks for any replies!

You can override drawLabel to achieve any desired effect. Invoke getFontMetrics() on the parameter g2 to position the text precisely. The JCommon class TextUtilities, used extensively in JFreeChart, may offer more convenience.

Swing: Which objects for a multi panel display and highlighting text

I plan on making a multi comparison program. It will compare multiple files by displaying N number of files in a grid where N = X * Y. X and Y are the width and height of the grid elements. Easy enough, I know how to do this pretty much.
The question:
How do and in what way is best to highlight individual characters in each of these grid elements? I plan on highlighting matching text that is found in the same position.

I'd use a JTextPane rather than a JTextArea, and read up on the StyledDocument class. This will give you all sorts of options.

You could use a JTextArea with a Highlighter. See the second example on this page for how.

I'm not sure what you mean by "Highlight the characters", but to bring attention to grid elements, or pairs of grid elements, you could set the background color of the appropriate component.