Represents the Position and Size on Screen of an Form
poDesigned - The Form appears exactly as it is positioned and sized in the Form Designer
poDefault - The window manager decides how the form is to appear, in a default position and size
poDefaultPosOnly - keeps the Designed size, but position determined by windowmanager
poDefaultSizeOnly - keeps the Designed position, but size determined by windowmanager
poScreenCenter - Centers the form on screen
poDeskTopCenter - Centers the form on desktop
poMainFormCenter - Centers the Form on the Main Form
poOwnerFormCenter - Centers the Form on Owner form
Represents the actual State of the window on the screen
wsNormal - The window appears normal
wsMinimized - The window appears minimized
wsMaximized - The window appears maximized
TCustomForm.OnClose
Exception in Scroll Bar
Exception class for Scroll Bar
Control Scroll Bar
Control Scroll Bar: Scroll Bar control for adding to windows. Can be horizontal or vertical.
This is an ancestor class for many form types and classes of windowed controls
Create an instance of a Scroll Bar Control
The identity of the windowed control in which the scroll bar is found
Whether this is a horizontal or a vertical scrollbar
Finds some properties of the control bar from the source control
Assigns the contents of the source object to the current object; in particular finds the increment, position, range and whether smooth scrolling is to be feature and whether the scroll bar is visible
The object that called this instance of the class
Visibility of scroll bar
Returns 'True' if scroll bar visible
Position of the indicator cursor on the scroll bar
Returns position of the scroll cursor as an integer
Finds which kind of scroll bar this is: horizontal or vertical
Reads a flag to determine which kind of scroll bar
Finds out details of the other scroll bar
Returns a link to the details of the other scroll bar
Find out details about the horizontal scroll bar
Returns details of the horizontal scroll bar as a pointer to a structure
Find out details of the vertical scroll bar
Returns details of the vertical scroll bar as a pointer to a structure
Determine the size of the scroll bar
Reads or writes a flag to determine the size; by default the size is not stored
The size of the scrolling increment
The amount by which the scroll indicator moves if the triangle at either end of the bar is selected.
Read or write a flag to determine the increment, an integer with a default value of 8 (pixels)
The size of the paging increment for scrolling
The amount by which the scroll indicator moves if the cursor selects the scroll bar above, below or on either side of the scroll indicator.
Reads or writes a flag to determine paging increment; default value is 80 pixels
Determine whether smooth scrolling is to be implemented
Reads or writes a flag to determine smooth scrolling, and sets a flag is the scrolling status is stored
Position of the scroll bar
Reads or writes a flag with the position; default is zero
The range (extent) of the scroll bar
Reads or writes a flag to determine the range; default is zero
Is the scroll bar visible?
Reads or writes flag to determine visibility, and sets a flag if the property is stored
Scrolling Window Control
Scrolling Window Control: A window control with scroll bars.
An ancestor class for many forms with scrolling windows
Create an instance of a scrolling window control
This constructor can override the constructor of an ancestor class
The component that owns the scolling window control
DEstroy this instance of scrolling window control, and free its resources
Can override destructor of parent class
Update the position of the scroll indicatores in the scroll bars
Checks if the scroll bars are in process of being loaded or destroyed;
if so, or if there is no valid handle, exit.
If the indicators are valid, re-computes position etc
Does auto-scrolling apply?
Reads or writes a flag to determine auto-scrolling
Scroll Box
Scroll Box: A box with scroll bars
Custom Frame
Custom Frame: The base type for Frame
Frame
Frame - a container for all the other components on a form, or for a group of components within a form
Specifies which icon appears on the top border of the Form
biSystemMenu - The form has a System menu (Maybe not all windowmanager supports this)
biMinimize - The form has an minimize button
biMaximize - The form has a maximize button
biHelp - When you click this button a Question Cursor appears and the help routines are called if you click on an control
Custom Form
Custom Form - the base type for FORM
Is true when the form has the focus
Use active to check if the form has the focus
Specifies the active control on the form
Use this to get or set the active control on this form
Specifies which icons appear on the top of the form
Use bordericons flags to get or set the icons that appear on the top border of the form.
By default we see down-triangle or other generic icon on the left,
which activates a pop-up system menu allowing closure or re-sizing of the form,
and on the right end we see the minimise and re-size/maximise buttons,
but of course these can be customised by the application programmer.
Specifies the appearance of the form's border
Use borderstyle to get or set the appearance of the form's border.
By default it is a sizeable window, but it could, for example, be a dialog form or a tool window, or could be non-sizeable
The control associated with the cancel action
Reads or writes a flag to determine the control associated with the Cancel action (exit from the control without changing anything).
This is usually a button with the caption 'Cancel', but might be an 'Exit' button or anything else the application programmer decides..
This control is selected either by explicitly clicking with the mouse, or by hitting the 'Esc' key
The colour of the form
The form's colour; by default it is the same as the colour specified for button faces.
The control associated with the default action for this form
Reads or sets a flag determining the default control.
This is typically a button such as 'Accept' which is highlighted in some way on-screen to indicate that this is the default action, and is selected either by hitting 'Return' or 'Enter' or by selecting that control with the mouse
Determines the state of the form
Reads or writes a flag to determine the form's state:

is it being created, is this its first showing, is the border style being changed, etc.

FormState is a set, so could take zero or more of possible values.
Determinates the style of the form
Reads or writes flag to determine the style of the form.

Default is 'normal', but could be MDIChild or MDINormal,

could stay on top or could be a 'Splash' form.

FormStyle is a set, could take zero or more of these values.
Specifies the help file that is used by the form
Reads or writes a flag to determine identity of Help file,
and to determine whether its name is stored.
Property contains filename as a string.
Specifies a MainMenu for this form
Drop a TMainMenu on the form and select it here to show it on the form.
Specifies the return value of an modal form
Reads or writes a flag to determine whether there is a modal resut.
If the form is modal, returns an integer value.
The scaling of the form in proportion to the screen resolution
Reads or writes a flag to determine the scaling factor (a longinteger).
Not normally stored locally
The position of the form on the screen
Reads or writes a flag to determine screen position of form.

By default it is in the position that it was placed in the Form Designer
Indicates if the form is visible
Set or get this to set the form visible/hidden or get the status of the form
Represents how the form appears on the screen
Reads or write flag to determine state of the window on screen.

Default is 'normal' (ie not minimised or maximised)
Form
Form - the fundamental visual object that appears in every GUI application.
Most of the properties are inherited from the ancestors
Specifies the control that has the focus on the form
Use active control to set or get the control that has the focus on this form
Hint Window
Hint Window - the popup box containing helpful information that appears when the mouse pointer hovers over an object
Screen
Screen - the visible area
Specifies which style the form border has
Create an instance of TScreen
Destroy this instance of TScreen
The Index number of a Custom Form on the screen
The Index number of the Custom Form, stored as an integer
The Custom Form to which the Index refers
The index number of a Form on the Screen
The index number of the Form, stored as an integer
The Form to which the Index refers
Method for updating screen
The identity of the active control on this screen
Reads a flag to determine the active control
The identity of the active Custom Form on this screen
Reads a flag to determine the active Custom Form
The identity of the active Form on this Screen
Reads a flag to determine the active Form
The cursor being used in this screen
Reads or writes a flag to determine the cursor.
This can take any integer value, but there are several pre-determined cursor styles
listed as constants in 'Controls',
and these should be used to define the cursor for the current screen
The number of Custom Forms on this screen
Reads flag to determine number of Custom Forms (integer)
The number of Forms on this screen
Reads a flag to determine the number of Forms (integer)
The list of Forms in this Screen
Index number of a Form, stored as an integer
The fonts to be used in this screen
Reads a flag to determine the fonts to be used; their names are stored as a list of strings
The height of the screen
Reads a flag to determine screen height; stored as an integer
The font to be used to display hints
Reads a flag to determine the font to be used (font name stored as a string)
The width of the screen
Reads flag to determine screen width, stored as an integer
Scaling factor for displaying graphic information on the screen
Reads a flag to determine number of pixels per inch (integer)
Application - the whole current program, described as an object
Application - the whole current program, described as an object.
Includes useful function MessageBox, a simple dialog
Create an instance of TApplication
This instance of the constructor performs most of the setting up of the environment for the application. The instances of Create that occur in some of the ancestor classes are place holders rather than actual instructions for constructing the object
The Owner object that invoked this instance of TApplication
Destroy this instance of TApplication and free its resources
Method for dealing with a control that has been destroyed
Use the selected widget set's method to bring the application's form(s) to the front
Create Form or any other kind of component
Note: The name is confusing and only kept for Delphi compatibility.
It can actually create any kind of component
Creates a Component instance, sets the pointer to the component variable and loads the component.
If it is a form it will be added to the application's forms list
Insert a given asynchronous call into the queue
The method to be used for the asynchronous call
The data structure used by the asynchronous call method
The method to be used to execute the action associated with the Application
This is a function that should be supplied by the application programmer, to override the placeholders declared in ancestor classes
Exception handler - methods to be followed in response to exceptions
Individual exception handler methods should be supplied by the application programmer, to override place-holder entries declared in ancestor classes.
This method checks whether the application is required to halt if an exception occurs, or invokes the appropriate handler.

It also writes details of the exception to the appropriate place for debugging.
Process all events according to the method defined for the widget set
Cancels a request for a hint, if there is no hint timer or no hint to display
Don't display the hint
the icon to be associated with this application
Reads or writes a flag to determine the Icon
Initialize any forms associated with the application
Finds the appropriate widget set, reads the application's icon (if any) from the Lazarus Resource file, initialises the screen, and leaves it ready for processing.
Message Box
Message Box: a useful function to display a message.
The function is used internally to display messages during the handling of Exceptions, but is also available to application programmers as an alternative to some of the message dialogs found in Dialogs.
The function returns an integer value corresponding to the button that was pressed; its value can be determined by reference to the constants [IDOK..IDHELP]
It can be invoked like a procedure call (ie as a 'MessageBox()' statement rather than as a 'Variable := MessageBox()' function call)
Result
Result: integer value returned by the function to signify which box was selected
Can be one of the following values:
IDOK
IDCANCEL
IDABORT
IDRETRY
IDIGNORE
IDYES
IDNO
IDCLOSE
IDHELP
Text
Text: the string that is displayed as a prompt or instruction in the Box;
Caption
Caption: the string label at the top of the message box;
Flags
Flags: longint - an integer constructed by adding together various constants to define the contents and behaviour of the box, for example
MB_ABORTRETRYIGNORE + MR_ICONQUESTION will cause the application to display a query (?) icon in a box with three buttons:
ABORT RETRY IGNORE.
The following button constants are available:
MB_OK
MB_OKCANCEL
MB_ABORTRETRYIGNORE
MB_YESNOCANCEL
MB_YESNO
MB_RETRYCANCEL
And the following icon constants:
MB_ICONHAND
MB_ICONQUESTION
MB_ICONEXCLAMATION
MB_ICONASTERICK
MB_ICONWARNING = MB_ICONEXCLAMATION
MB_ICONERROR = MB_ICONHAND
MB_ICONSTOP = MB_ICONHAND
MB_ICONINFORMATION = MB_ICONASTERICK
These constants are declared on the LCLType unit.
Minimise the form using the widget set's method
the method to be used to make the application execute.
This method should be supplied by the application programmer, and should be the main process control procedure for the application
Show any exception that has occurred
The exception that is to be displayed
If exceptions have occurred, find out what they are, ready for processing
The hint associated with the main application
A hint is a small pop-up mesage that appears briefly while the mouse hovers over a specified area of the screen. It usually displays useful information about how to use an object or what data should be entered, etc
Reads or writes a flag to determine the hint associated with the application
The colour used to display the hint
The delay period after mouse entry before the hint becomes visible
The length of time for which the hint is displayed
Determine how the form is to be navigated
Reads or writes a flag to determine the navigation method:
Is Tab used to move to next control?
Does Enter or Ret activate the default action?
Does Esc perform the cancel action?
Does F1 activate a Help system?
Navigation Options is a set, so can take zero or more of the available values
The Main Form used by the application for process control and for data input/output
Reads a flag to get particulars of the main form
The Title to be displayed in the top border of the Main Window
Reads or writes a flag to determine the Title string
Application Properties
Application Properties: The properties of the current application
Create an instance of TApplication Properties
Determine whether exceptions are being captured
Boolean property (true if exceptions are being captured); reads or writes flag to see if they are being captured
Determines which file to use for Help
Reads or writes flag to determine name of Help file - name is stored as a string
Determines Hint to be used
Reads or writes flag to determine Hint - stored as a string
Colour to be used when displaying Hint
Reads or writes flag to determine Hint colour (stored as a TColor integer)
Determines whether a hint is to be displayed
Read or write flag to determine whether to display hint (stored as boolean, True if hint is to be displayed)
Title to be shown in Application's top Border
Data Module
Data Module: for interfacing to the database