TPJWdwState & TPJRegWdwState Components

Contents

• Description
• Compatibility
• Installation
• Known Issues
• Update History
• Credits
• License and Disclaimer
• About the Author

Description

The file PJWdwState.pas includes two components - TPJWdwState and TPJRegWdwState.

The components can save the state (minimised, maximised or normal) of a form window, along with its size and position. TPJWdwState saves the information to an ini file while TPJRegWdwState saves to the registry. The components can also read information back and restore the saved window settings. This means the components can be used to restore a window to the condition it was in during some previous execution. This is acheived either by calling a couple of methods within code or setting the component to automatically save and restore the window on creation and destruction.

With TPJWdwState you can specify the name of the ini file, or let the component choose one. You can also decide the name of the section within the ini file that will be used. Again the component can provide a suitable default section name.

Similarly with TPJRegWdwState you can specify the registry root and sub-keys under which the information is saved. Again suitable default values are used if no keys are specified.

Also included in the PJWdwState.pas unit is the component TPJCustomWdwState along with a helper component. Neither of these components should be constructed directly and they are not registered with Delphi.

The zip file that contains PJWdwState.pas also contains an optional property editor in PJHKeyPropEdit.pas (TPJHKEYPropEditor) for editing the registry root key property of TPJRegWindowState.

Compatibility

The components and property editor have been tested with Delphi 4, 6 and 7. It is likely that they will work with Delphi 3 and 5, but this has not been tested. They are not compatible with Delphi 1 and 2.

Installation

In these instructions $(DELPHI) is to be taken to represent the path where the appropriate version of Delphi was installed. For example, if you have Delphi 4 installed on the default installation path then $(DELPHI) is equivalent to C:\Program Files\Borland\Delphi4.

To install, proceed as follows:

1. Unzip the .zip file containing the components into a folder, preserving the directory structure.
2. Copy PJWdwState.pas and PJWdwState.dcr to the folder from where you wish to install the component into the Delphi Component Palette. This will probably be a sub-folder of the $(DELPHI)\lib folder.
3. If you wish to install the optional HKEY component editor contained in PJHKEYPropEdit.pas then copy this file to the same folder as PJWdwState.pas.
4. Install the components and, optionally, the property editor, by chosing the Component | Install Component menu option then:
   • Select the "Into exisiting package" page of the Install Components dialog box.
   • Browse to the folder where you saved PJWdwState.pas and select the file.
   • Select the package into which you wish to install the component.
   • If installing the property editor, repeat the above process with PJHKEYPropEdit.pas.
   • Accept that the package will be rebuilt.
   • A dialog box should be displayed saying that TPJWdwState and TPJRegWdwState have been added to the component palette. If you have installed the property editor no confirmation of installation will be displayed.
5. You can now delete PJWdwState.pas (and PJHKEYPropEdit.pas if installed) from the place where you copied them if you wish. The components will appear on a palette called DelphiDabbler. You can move the components to a different palette as required.
6. The simplest way to install the help file is to use my Component Help Installer Expert. To install manually, proceed as follows:
   • Copy PJWdwState.hlp to whichever folder you wish to install it to.
   • In Delphi 3 to 6 (where X is the Delphi version 3..6):
     • Edit DelphiX.ohl (in $(DELPHI)\Help), adding the line :Link PJWdwState.hlp to the end of the section labelled "Third party help".
     • Edit DelphiX.ohi (in $(DELPHI)\Help), adding the line :Index DelphiDabbler Window State Components=PJWdwState.hlp towards the end of the index section.
     • Edit DelphiX.cnt (in $(DELPHI)\Help), ensuring that the lines :Include delphiX.ohi and :Include delphiX.ohl appear somewhere in the file.
   • In Delphi 7:
     • Edit D7.ohl (in $(DELPHI)\Help), adding the line :Link PJWdwState.hlp to the end of the section labelled "Third party help".
     • Edit D7.ohi (in $(DELPHI)\Help), adding the line :Index DelphiDabbler Window State Components=PJWdwState.hlp towards the end of the index section.
     • Edit D7.cnt (in $(DELPHI)\Help), ensuring that the lines :Include d7.ohi and :Include d7.ohl appear somewhere in the file.
   • Using RegEdit open the key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Help and add a new string value named PJWdwState.hlp whose value is the path where you copied the help file (probably ($DELPHI)\Help).

Known Issues

• No known outstanding bugs.

Update History

Release 4.2 of 30 October 2003
PJWdwState v4.1 of 30 October 2003
PJHKeyPropEdit v1.0.2 of 30 October 2003

• Added new option to Options property to ensure window is not displayed out of the desktop's work area.
• Some changes made to way registry is accessed in TPJRegWdwState.
• Rearranged some decision logic.
• Changed component palette to 'DelphiDabbler' from 'PJSoft'.

Release 4.1 of 07 August 2002
PJWdwState v4.1 of 07 August 2002
PJHKeyPropEdit v1.0.1 of 08 October 2000

• Added new OnReadWdwState event in which user can override window placement, size and state read from registry or ini file.
• Added new Options property which contains a set of values that govern the behavoiur of the component. The options are to ignore the stored window state and ensure window is displayed normally or ignore the stored window size and use the form's size as designed.

Release 4.0 of 17 March 2002
PJWdwState v4.0 of 17 March 2002
PJHKeyPropEdit v1.0.1 of 08 October 2000

• Made use ParamStr(0) for default name of ini file and registry key.
• Changed name of default registry sub key and ini file section to enable use of multiple forms without overwriting each other's data when using default property values.
• Rewrote method of auto saving and restoring windows to stop having to manipulate the owning form's OnCreate and OnDestroy event handlers. Now uses a hook class to hook into owning form's messages and pass them to window state components. The window now always momentarily appears in normal state before being maximized or minimized as required.
• Added new MinimizeDelay property to control how long the normal window appears before being minimized.
• Added OnGetIniData event to TPJWdwState and OnGetRegData events to TPJRegWdwState to allow user to override property values for reading / writing ini file and registry.
• Made so that now only one instance of a window state component can be placed on a form.
• Rationalised some elements of code.
• Changed component palette from 'PJ Stuff' to 'PJSoft'.
• Changed unit name to PJWdwState.
• Rewrote help file to integrate into Delphi 3+ IDE, removing support for Delphi 2 IDE..

Release 3.1.1 of 08 October 2000
WdwState v3.1 of 29 April 2000
PJHKeyPropEdit v1.0.1 of 08 October 2000

• Added property editor for TPJRegWdwState's RegRootKey property.

Release 3.1 of 29 April 2000
WdwState v3.1 of 29 April 2000

• Fixed a bug where windows that were supposed to be restored maximised to be displayed using the last saved window dimensions. This bug was also causing the form to fail to load other components under certain circumstances. (thanks to Andre Viol for reporting these bugs).

Release 3.0 of 05 April 2000
WdwState v3.0 of 05 April 2000

• Added AutoSaveRestore property to enable forms to be automatically savedand restored (thanks to Stefan Winter for suggesting this and providing prototype code).
• Modified window restoration code to avoid task bars in positions other than bottom of screen (again thanks to Stefan for pointing out the problem and providing prototype code to fix it).
• Prevented forms being restored as minimized from flashing on screen (by cheating!)
• Removed conditional compilation statements since this version will not compile under Delphi 1.

Release 2.1 of 29 November 1999
WdwState v2.1 of 29 November 1999

• Renamed ReadState and SaveState methods to ReadWdwState and SaveWdwState respectively since ReadState was masking a method inherited from TComponent.
• Updated HTML documentation to include installation notes for Delphi 3/4 and added update history.

Release 2.0 of 19 October 1999
WdwState v2.0 of 19 October 1999

• Re-write which added TPJRegWdwState component that stores window state information in registry.
• Extracted common functionality of TPJWdwState and TPJRegWdwState into new abstract base class TPJCustomWdwState.
• TPJWdwState presented same interface and functionality as version 1.
• TRegWdwState was not available when compiled under Delphi 1 (because it uses the registry).
• Updated HTML documentation to deal with new classes.

Release 1.0 of 15 August 1999
WdwState v1.0 of 15 August 1999

• Original version - included just TPJWdwState component with HTML documentation.

Credits

• Thanks are due to Stefan Winter for providing some of the code of version 2.2 and for adding a prototype version of the AutoSaveRestore property. Stefan also suggested adding the OnGetIniDate and OnGetRegData events - implmented in v4.0
• Andre Viol suggested that the normal window should flash on screen before minimizing and maximizing as required.

License & Disclaimer

These components are copyright © P.D.Johnson, 1999-2003.

The source code and help files can be freely distributed on a not-for-profit basis providing that:

1. The source code is not altered.
2. This readme file is distributed with it unchanged.

By not-for-profit I mean that you may recover out of pocket expenses incurred in distributing the code, but should not make a profit from this.

If you discover any bugs in this implementation, or if you have any update suggestions, please contact me via my website.

Please do modify the code for you own use. I'd like to see any changes you make - I could incorporate them into future versions. Please notify me of changes on at the above e-mail address.

This software is provided as is - no warranty is given as to its suitability for any purposes to which you may wish to put it.

About the Author

I'm Peter Johnson - a hobbyist programmer living in Ceredigion in West Wales, UK. I write mainly in Delphi. My programs are available for download on my web-site: http://www.delphidabbler.com/.

I can be contacted via the website.