Tag Archives: TApplicationEvents

Implementing Custom Hint For Each Panel on a Status Bar

TStatusBar.Panel.HintAs the Help states, The TStatusBar Delphi control displays a row of panels, usually aligned at the bottom of a form. Each panel is represented by a TStatusPanel object listed in the Panels property.

Much like any other VCL control, the TStatusBar can be adopted and extended to offer greater functionality. A simple case would be to use the status bar to display long hints from other controls.

What does not come out of the box is the possibility to have each panel on a status bar display its own hint (tooltip) when the mouse “stops” over a panel.

Even though the TStatusBar provides the Hint and ShowHint properties to let you assign the tooltip text which appears when the user moves the mouse over the control – you cannot have each panel on a status bar have its own specific hint!

You cannot? You can! Here’s how to implement TStatusPanel.Hint for each panel on a status bar…
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Graphical Hints – Image in Virtual Treeview Node Hint (Extending TVirtualTreeHintWindow)

delphi-vtw-pdf-hint-graphics-previewIn a Delphi application, the THintWindow class implements the small pop-up window that appears over a control at run time, when the control has its ShowHint property set to True (and has a value assigned to the Hint property).
The implementation of the THintWindow (at least what gets displayed by it, not how) is rather simple: it will display whatever string value is assigned for the Hint property of a control. If you want more control over what gets displayed by the hint window, and how, and when the hint window will popup – you can create your own version by extending the THintWindow class.
To use your own hint you would assign your own class to the global HintWindowClass variable at application start-up time, so that the new hint window type is used for hints. You can even fine tune the display of the hint window just before it pops-up using the OnHint and OnShowHint events of the TApplicationEvents.

That’s all nice and clear. But, what if the control you are using is Virtual Treeview which has its own version of the hint window implemented in TVirtualTreeHintWindow? What if you want to extend this by including some graphics along with the text that the hint window displays? Further, what if you need to have different hint values for every node displayed by the tree?
Of course, you are not working on a new application – all logic is already there, lots of methods and events already implemented.

The answers: here’s how to simply extend both the TVirtualTreeHintWindow and the TVirtualStringTree to add some node specific graphics to the hint window displaying node specific hints.
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Have Hints For Some Delphi Controls Stay Longer – Control Specific Hint Hide Timeout Values

hint-hide-timeout-delphiAh, even after years of programming in Delphi, there’s still something new I learn every day (lucky me).

Just recently I needed to have hints (help tooltips) for some buttons to stay visible longer than hints for other controls (like edits, memos and alike).

Found no straight forward solution here…
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