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VCL Components
The Font dialog box has a single event, OnApply, that will occur when the user clicks the Apply
button on the Find dialog box. The Apply button will not be present on the Font dialog box
unless you have first created a valid (not empty) event handler for the OnApply event.
The Find and Replace Dialog Boxes
The Find and Replace dialog boxes provide users the capability to enter text to search for and
text to replace the found text with, and a variety of search and replace options. The Find dialog
box is encapsulated in the VCL component FindDialog, and the Replace dialog box is
represented by the ReplaceDialog component. The Replace dialog box, which contains
everything found on the Find dialog box, plus the extra replace features, is shown in Figure
8.11.
Figure 8.11.
The Replace dialog box.
Major properties of the FindDialog and ReplaceDialog components include FindText (the
text to find), ReplaceText (the text with which to replace the found text), and Options.
Obviously, the FindDialog does not have a ReplaceText property. The Options property
contains a wide variety of information about the various options that the user had set at the
time the Find Next, Replace, or Replace All button was clicked.
The Execute() method for the FindDialog and ReplaceDialog components is a little different
than it is with the other common Dialog components. First, the Find and Replace dialog
boxes are modeless dialog boxes. As soon as the dialog is displayed, the Execute() method
returns. Because the dialog is modeless, the return value from Execute() is meaningless (it’s
always true). Instead, the Find and Replace dialog boxes use the OnFind and OnReplace events
along with the Options property to determine what is happening with the dialog box. The
OnFind event occurs when the Find Next button is clicked. The ReplaceDialog has an OnFind
event, but it also has an OnReplace event that is fired when the Replace or Replace All button
is clicked. Use these events to determine when the user has requested a find or replace action.
Your programs should read the Options property to determine how the user intended the find
or replace operation to be carried out.
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