dbFieldLink Class Reference
[OOFILE GUI forms interface.]

#include <oofgui.h>

Inheritance diagram for dbFieldLink:

[legend]Collaboration diagram for dbFieldLink:

[legend]List of all members.

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Detailed Description

dbFieldLink is the main link abstraction mapping a database field to a GUI object (via a dbGUIAdapter).

This two-stage mapping is necessary so we can provide overrides at either end without a combinatorial explosion from mixing field and GUI control types. (As early OOFILE suffered.)

In Pattern terms, dbFieldLink provides a Facade covering a whole range of field access. dbGUIAdapter is our Adapter for control I/O interfacing.

Warning:

most of the methods of dbFieldLink operate under the original assumptions that the field link has been initialised with both a dbField* and dbGUIAdapter*.

Report editing may subclass and use with NULL values for either of these, but uses only a subset of features.

We implement read-only in OOFILE rather than relying on application level controls as some frameworks (eg: PowerPlant) may not provide readonly behaviour without having to totally disable a control. If you want to retain select/copy/paste of a control, disabling is not suitable.

dbFieldLink retains the setting and can be queried by isReadOnly. Implementing the behaviour to inhibit editing is the job of the dbGUIAdapter eg, in PowerPlant dbGUIAdaptEditPane::ExecuteSelf swallows msg_KeyPress.

Note:

it is quite straightforward to use your own subclasses of dbFieldLink. Rather than using dbEditHelper::linkField to link the control and dbField, create your own link and give it to the helper:

    mEditHelper->adoptLink(new YourLink(...));

mainly used by dbGUIadaptor
void	maybeChangeTargetLink ()
void	maybeDirty ()
virtual void	tellGUIcareAboutLocking () const
mainly used by dbEditHelper
virtual void	copyFieldToLink ()
virtual void	copyLinkToField ()
virtual bool	linkEqualsField () const
virtual bool	leaveLink ()
virtual void	updateDerivedFieldDisplay (bool isNew)
virtual void	readOnly (bool isReadOnly=true)
	Change readonly state of link to accept or deny data entry.
virtual bool	validToLeaveLink ()
	Validate field contents, overridden if can check just contents.
virtual bool	validToLeaveForm ()
	Validate unique fields to ensure can accept this record without error from database.
virtual void	highlightLink ()
	Visually highlight a link, usually becoming edit focus.
void	markClean ()
reflective calls
bool	isReadOnly () const
bool	alwaysReadOnly () const
bool	isDirty () const
bool	linkIsEmpty () const
dbGUIAdapter *	adapter () const
Public Member Functions
	dbFieldLink (dbField *, dbGUIAdapter *adoptedAdapter, bool becomeReadOnly=false)
	dbFieldLink (const dbFieldLink &)
virtual	~dbFieldLink ()
dbHelper *	owner () const
void	owner (dbHelper *)
	not ctor param as can create without helper
dbField *	field () const
	purposely non-virtual as subclasses return different types
void	setField (dbField *inField)
bool	hidden () const
void	hide (bool hideIt=true)
virtual void	describe (std::ostream &) const
	Provide human-readable information about object.
virtual oofString	name () const
Protected Attributes
dbField *	mField
dbGUIAdapter *	mAdapter
	owned
dbHelper *	mOwner
bool	mMaybeDirty
	tentative flag lets us optimise comparisons
bool	mReadOnly
	default is read-write
bool	mAlwaysReadOnly
	for static controls, etc;
bool	mHidden
Friends
class	dbAbstractEditHelper
	so it can call PreApprovedReadOnly

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Constructor & Destructor Documentation

dbFieldLink::dbFieldLink (  dbField *  fld, dbGUIAdapter *  adoptedAdapter, bool  becomeReadOnly = false )

Parameters: adoptedAdapter  is our interface to a source/display of values (probably control) becomeReadOnly  indicates the control must not allow update of the field.

dbFieldLink::dbFieldLink (  const dbFieldLink &   )

dbFieldLink::~dbFieldLink (   )  [virtual]

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Member Function Documentation

dbGUIAdapter * dbFieldLink::adapter (   )  const [inline]

bool dbFieldLink::alwaysReadOnly (   )  const [inline]

void dbFieldLink::copyFieldToLink (   )  [virtual]

Reimplemented in dbFieldPickLink, and dbBoolLink.

void dbFieldLink::copyLinkToField (   )  [virtual]

Reimplemented in dbFieldPickLink, and dbBoolLink.

void OOF_PublicBase::describe (  std::ostream &  os  )  const [virtual, inherited]

Provide human-readable information about object. Overriden to provide much more detail particularly for dbTable::describe() which provides full schema. Reimplemented in dbTable, dbConnect, dbField, dbChar, dbFixedBinary, and dbRelRefBase.

dbField * dbFieldLink::field (   )  const [inline]

purposely non-virtual as subclasses return different types Used by dbGUIAdapters such as dbGUIAdaptEditPane::setFieldLink to get the field in order to query database characteristics. Returns: dbField* to the field we link. Reimplemented in dbUshortLink.

bool OOF_PublicBase::hidden (   )  const [inline, inherited]

void OOF_PublicBase::hide (  bool  hideIt = true  )  [inline, inherited]

void dbFieldLink::highlightLink (   )  [virtual]

Visually highlight a link, usually becoming edit focus. dbAbstractEditHelper::ValidateLinks calls us to highlight the first invalid link it finds.

bool dbFieldLink::isDirty (   )  const [inline]

bool dbFieldLink::isReadOnly (   )  const [inline]

bool dbFieldLink::leaveLink (   )  [virtual]

Reimplemented in dbFieldPickLink, and oofRepEditLink.

bool dbFieldLink::linkEqualsField (   )  const [virtual]

Reimplemented in dbFieldPickLink, and dbBoolLink.

bool dbFieldLink::linkIsEmpty (   )  const

void dbFieldLink::markClean (   )  [inline]

void dbFieldLink::maybeChangeTargetLink (   )  [inline]

void dbFieldLink::maybeDirty (   )  [inline]

oofString OOF_PublicBase::name (   )  const [virtual, inherited]

Reimplemented in dbTable, dbConnect, dbField, and OOF_adornerHolder.

void dbFieldLink::owner (  dbHelper *   )  [inline]

not ctor param as can create without helper

dbHelper * dbFieldLink::owner (   )  const [inline]

void dbFieldLink::readOnly (  bool  becomeReadOnly = true  )  [virtual]

Change readonly state of link to accept or deny data entry. Won't allow enabling editing if can't edit record due to locking.

void dbFieldLink::setField (  dbField *  inField  )  [inline]

void dbFieldLink::tellGUIcareAboutLocking (   )  const [virtual]

Reimplemented in oofRepEditLink.

void dbFieldLink::updateDerivedFieldDisplay (  bool  isNew  )  [virtual]

Reimplemented in dbNumericFieldLink, dbDateLink2Editor, and dbDateTimeLink2Editor.

bool dbFieldLink::validToLeaveForm (   )  [virtual]

Validate unique fields to ensure can accept this record without error from database. Warning: you probably still want to call this method if you override. Reimplemented in dbFieldPickLink.

bool dbFieldLink::validToLeaveLink (   )  [virtual]

Validate field contents, overridden if can check just contents. Lightweight check that allows tabbing between fields in open record. See also: validToLeaveForm for heavier check. dbDateLink2Editor::validToLeaveLink Reimplemented in dbDateLink2Editor, and dbDateTimeLink2Editor.

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Friends And Related Function Documentation

friend class dbAbstractEditHelper [friend]

so it can call PreApprovedReadOnly

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Member Data Documentation

dbGUIAdapter* dbFieldLink::mAdapter [protected]

owned

bool dbFieldLink::mAlwaysReadOnly [protected]

for static controls, etc;

dbField* dbFieldLink::mField [protected]

bool OOF_PublicBase::mHidden [protected, inherited]

bool dbFieldLink::mMaybeDirty [protected]

tentative flag lets us optimise comparisons

dbHelper* dbFieldLink::mOwner [protected]

bool dbFieldLink::mReadOnly [protected]

default is read-write

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The documentation for this class was generated from the following files:

• oofgui.h
• oofgui.cpp

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