GUI design guidelines
Dialogs are special forms that need the user to make / change some setting before lazarus can continue.
Settings that should be applied in general are;
- BorderStyle : bsSizeToolWin
- Position : poScreenCenter
- FormStyle : Do not use fsStayOnTop, as this can be pretty annoying under some window managers.
Show the dialog using ShowModal
- On the bottom all required buttons to close / cancel the dialog, or to recieve help should be placed
- The dialog should work on a screen of 800x600. 640x480 is not needed to support.
- Close on Escape (if key not used otherwise)
- Define default button and Return activates it (if key not used)
- All but the most simple dialogs should be resizable and size is stored
The button panel should consist at least of the following elements;
- OK button (or better: a describing text like 'Save' or 'Rename')
- Cancel button
- Next button (optional)
- Previous button (optional)
- Help button
An example is shown below:
To make sure that a dialog after resizing will keep on showing the components in a good way, anchoring is being used. Each components has a property called Anchors. With this property you can determine the way a component is anchored to it's parent.
Hint: Use the anchor editor of the IDE.
Another way to organise components is using alignment. Each component has a property Align. By selecting the appropriate align position several components can be positioned properly.
Especially useful in combination with Align is the BorderSpacing property. (Also found on the Anchors dialog). A typical borderspacing of 6 pixels around a component is used.