Class CCoeTextDrawerBase

class CCoeTextDrawerBase : public CBase, public MObjectProvider;

Description

This is the base class for all text drawers implementing different text effects (for example shadow or glowing/outlined text). The object can be created and deleted each time it's used, or Reset() and reused if it IsReusable(). The latter is recommended.

Note that the pure virtual DrawText() method is private. This ensures that the object is used through the XCoeTextDrawer class (which manages its life).

Note also that the accessor and set methods should be used via the owning XCoeTextDrawer object, and that the MObjectProvider mechanism can be used to identify the actual text drawer implementation.

Derivation

• MObjectProvider - An interface that allows an object to be part of a network of object providers
• CBase - Base class for all classes to be instantiated on the heap

• CCoeTextDrawerBase - This is the base class for all text drawers implementing different text effects (for example shadow or glowing/outlined text)

Members

Defined in CCoeTextDrawerBase:
ActualHorizontalAlignment(), Alignment(), CCoeTextDrawerBase(), Construct(), DrawText(), EffectMargins(), IsReusable(), LineGapInPixels(), Margins(), Reset(), SetAlignment(), SetAppLanguage(), SetLineGapInPixels(), SetMargins(), SetReusable(), SetTextColor(), TextColor(), ~CCoeTextDrawerBase()

Inherited from CBase:
Delete(), Extension_(), operator new()

Inherited from MObjectProvider:
MObjectProvider_Reserved1(), MObjectProvider_Reserved2(), MopGetObject(), MopGetObjectNoChaining(), MopNext(), MopSupplyObject()

IMPORT_C ~CCoeTextDrawerBase();

Description

Destructor.

protected: IMPORT_C CCoeTextDrawerBase();

Description

Constructor.

virtual IMPORT_C void Reset();

Description

This method is called from the destructor of the XCoeTextDrawer object managing the life of the CCoeTextDrawerBase object, if the CCoeTextDrawerBase object has been set to be reusable (by its owner calling SetReusable()).

Any derived class must override this method to reset its drawing parameters to their defaults, so that the object is ready to be used again. Any overriding implementation must call the base implementation as well.

virtual TRgb TextColor() const=0;

Description

This method returns the main color used by the CCoeTextDrawer to draw text.

Return value

TRgb The color used to draw text.

virtual void SetTextColor(TRgb aColor)=0;

Description

This method sets the main color to use to draw text.

Parameters

TRgb aColor The color to use to draw text.

IMPORT_C TGulAlignment Alignment() const;

Description

Returns the text alignment that will be used by DrawText() and DrawDisplayOrderedText(). Note that left and right alignment will be swapped for right-to-left scripts, unless the alignment has been set to be absolute (see TGulAlignment).

A typical user of the text drawer mechanism will use the XCoeTextDrawer version of this API.

Return value

TGulAlignment TGulAlignment value of iAlignment data member

IMPORT_C void SetAlignment(const TGulAlignment &aAlignment);

Description

Set the text alignment that will be used by DrawText() and DrawDisplayOrderedText(). Note that left and right alignment will be swapped for right-to-left scripts, unless the alignment has been set to be absolute (see TGulAlignment).

A typical user of the text drawer mechanism will use the XCoeTextDrawer version of this API.

Parameters

const TGulAlignment &aAlignment TGulAlignment value.

IMPORT_C TMargins8 Margins() const;

Description

Returns the text margins that will be used by DrawText() and DrawDisplayOrderedText().

A typical user of the text drawer mechanism will use the XCoeTextDrawer version of this API.

Return value

TMargins8 The margins between the text rect and the actual text, in pixels.

IMPORT_C void SetMargins(const TMargins8 &aMargins);

Description

Set the text margins that will be used by DrawText() and DrawDisplayOrderedText().

A typical user of the text drawer mechanism will use the XCoeTextDrawer version of this API.

Parameters

const TMargins8 &aMargins The margins between the text rect and the actual text, in pixels.

IMPORT_C TInt LineGapInPixels() const;

Description

Returns the gap (in pixels) between lines of text. Default gap is 1 (one) pixel.

A typical user of the text drawer mechanism will use the XCoeTextDrawer version of this API.

Return value

TInt The gap between lines of text, in pixels.

IMPORT_C void SetLineGapInPixels(TInt aLineGapInPixels);

Description

Set the gap (in pixels) between lines of text. Default gap is 1 (one) pixel.

A typical user of the text drawer mechanism will use the XCoeTextDrawer version of this API.

Parameters

TInt aLineGapInPixels The gap between lines of text, in pixels.

IMPORT_C TBool IsReusable() const;

Description

Returns whether the CCoeTextDrawerBase-derived text drawer object has been set to be reusable or not. If reusable, the text drawer is assumed to have an owner that will delete it when appropriate. If not reusable, the XCoeTextDrawer will delete it in its destructor.

Return value

TBool bool value of iIsReusable data member

IMPORT_C void SetReusable(TBool aIsReusable);

Description

Set whether the text drawer is reusable or not. A reusable text drawer will be reset (through a call to Reset()) rather than deleted when the XCoeTextDrawer referring to it is deleted. This decision has to be made by the creator of the CCoeTextDrawerBase object. I.e. this method must not be called by a mere user of the XCoeTextDrawer.

Parameters

TBool aIsReusable Boolean indicating whether the text drawer can be re-used.

IMPORT_C void SetAppLanguage(TLanguage aAppLang);

Description

Unless absolute horizontal aligment has been selected (see TGulAlignment), the actual horizontal text alignment used when drawing text depends on whether the directionality of the scrip is left-to-right or right-to-left. In the latter case left and right is swapped. By default, the directionality of the actual text being drawn will define whether the horizontal alignment will be swapped or not. However, if (as recommended) the directionality of the application's main language shall be considered instead (rather than the directionality of the text being printed at the moment), then call this method.

If ELangNone is specified, the text drawer will be reset to swap horizontal alignment depending on the directionality of the text being printed.

Parameters

TLanguage aAppLang The application language (e.g. from CEikonEnv::ApplicationLanguage()).

protected: IMPORT_C TInt Construct();

Description

Second phase object construction. Note that this method is non-leaving as it may be called indirectly from a Draw() method, which must not leave.

Return value

TInt returns KErrNone if successful, otherwise KErrNoMemory.

protected: IMPORT_C TGulHAlignment ActualHorizontalAlignment(const TCoeTextTypeAdaptor &aText) const;

Description

This method returns the actual (absolute) horizontal text alignment to be used when drawing text in any CCoeTextDrawerBase-derived DrawText() implementation. The actual alignment depends on the application language directionality if the application language has been set calling CCoeTextDrawerBase::SetAppLanguage(), or otherwise on the directionality of the actual text being printed. If the directionality is right-to-left (and the horizontal alignment has not been set to be absolute, using TGulAlignment::SetAbsoluteHAlignment()), left and right alignment (set using XCoeTextDrawer::SetAlignment()) will be swapped.

Parameters

const TCoeTextTypeAdaptor &aText

Return value

TGulHAlignment

private: virtual void DrawText(CGraphicsContext &aGc, const TCoeTextTypeAdaptor &aText, const CFont &aFont, const TRect &aTextRect, const TRect &aClipRect) const=0;

Description

Any actual text drawer must implement this method to draw the text passed as argument. The implementation must draw the text inside the text rectangle, cropped to the clipping rectangle, and with the given margins and alignment taken into account.

Note that the actual horizontal alignment shall depend on the script directionality. Calling ActualHorizontalAlignment() will return the horizontal alignment where left and right has been swapped for right-to-left scripts.

Parameters

CGraphicsContext &aGc const TCoeTextTypeAdaptor &aText const CFont &aFont const TRect &aTextRect const TRect &aClipRect

virtual IMPORT_C TMargins8 EffectMargins();

Description

Any text drawer implementation must override this method, returning the "margins" that the text effect will add to the text extent. I.e. a one-pixel drop-shadow to the lower right will add an effect margin of TMargins8(0,0,1,1), while a one-pixel all-around outline will add an effect margin of TMargins8(1,1,1,1).

Return value

TMargins8