/*
* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
* This component and the accompanying materials are made available
* under the terms of "Eclipse Public License v1.0"
* which accompanies this distribution, and is available
* at the URL "http://www.eclipse.org/legal/epl-v10.html".
*
* Initial Contributors:
* Nokia Corporation - initial contribution.
*
* Contributors:
*
* Description: Definition of TAlfMetric, which is used to achieve
* text size dependent layouts, normalized child coordinate system and
* unified metrics system for all layout calculations.
*
*/
#ifndef __ALFMETRIC_H__
#define __ALFMETRIC_H__
#include <e32base.h>
#include <e32std.h>
#include <alf/alftextstylemanager.h>
/**
* Metric units. The unit defines how the @c iMagnitude member of the TAlfMetric
* struct is interpreted in practice. The interpretation may be dependent on
* the size of the layout where it is being used, the size of a font, or
* for example a globally defined constant.
*/
enum TAlfUnit
{
/** Real pixel that corresponds the pixels on the physical device screen. */
EAlfUnitPixel,
/** Normalized to parent layout size (0.0 -- 1.0). */
EAlfUnitNormalized,
EAlfUnitParentSize = EAlfUnitNormalized,
/** Relative to the display where the metric is being used (0.0 -- 1.0). */
EAlfUnitRelativeToDisplay,
EAlfUnitDisplaySize = EAlfUnitRelativeToDisplay,
/**
* Layout unit defined by S60 for a particular display device.
*/
EAlfUnitS60,
/**
* Relative to the size of the visual where the metric is being used (0.0 -- 1.0).
* This is particularly useful for anchor layout offsets, and for paddings.
*/
EAlfUnitRelativeToMySize,
EAlfUnitMySize = EAlfUnitRelativeToMySize,
/** relative weight; interpretation depends on sibling elements
* (for example, cells in a grid)
*/
EAlfUnitWeight,
/**
* Not supported at the moment.
* Line height of the font of the reference text style (the "em width")
*/
EAlfUnitLine,
/**
* Not Supported at the moment.
* Physical millimeters on the screen (for instance for icons).
*/
EAlfUnitMillimeter,
/**
* Similar to EAlfUnitMysize. Can be used for example to constrain the aspect ratio of a visual,
* by constraining one axis to be defined in relation to its orthogonal axis.
*/
EAlfUnitMyWidth,
EAlfUnitMyHeight,
/**
* Similar to EAlfUnitNormalized. Can be used for example to constrain the aspect ratio of a visual
* by constraining one axis to be defined in relation to its parent's orthogonal axis.
*/
EAlfUnitParentWidth,
EAlfUnitParentHeight,
/**
* Not Supported at the moment.
* Similar to EAlfUnitMysize. The minimum of a visual's dimensions.
*/
EAlfUnitMyDimensionMinimum,
/**
* Similar to EAlfUnitMysize. The Average of a visual's dimensions.
*/
EAlfUnitMyDimensionAverage,
};
/**
* A Metric is used to represent a value in a specified unit type. This is
* to support the definition of Layouts using screen-size independent as well
* as screen-size dependent measurements.
*
* The metrics are used for different things in different contexts:
* coordinate base units, anchor offsets, grid column/row weights, paddings, etc.
* The interpretation of the units used in the metric depends on the context,
* the type of Layout in which they are used, etc.
* Usage:
* @code
* TAlfMetric metricX(1.0, EAlfUnitNormalized);
* TAlfMetric metricY(2.0, EAlfUnitNormalized);
* //Set Layout base unit using Metrc
* layout->SetBaseUnit(metricX);
*
* //Create XYMetric using Metric
* TAlfXYMetric metricXY(metricX, metricY);
* //Set Layout base unit using XYMetrc
* layout->SetBaseUnit( metricXY );
*
* //Create Anchor offset as boxMetric
* TAlfBoxMetric offset(
* TAlfMetric(0.1, EAlfUnitMySize),
* TAlfMetric(-0.1, EAlfUnitMySize),
* TAlfMetric(0.1, EAlfUnitMySize),
* TAlfMetric(-0.1, EAlfUnitMySize));
* TAlfAnchorAttachmentOrigin attachmentOrigin(EAlfAnchorAttachmentOriginNone);
* TInt attachmentOrdinal(EAlfAnchorAttachToParent);
*
* //Attach anchor origin
* anchorLayout->Attach(ordinal, offset, attachmentOrigin, attachmentOrdinal);
* @endcode
*
*/
struct TAlfMetric
{
public:
/**
* Constructor. The constructor defaults to using [1px] units.
*
* @param aMagnitude the size of the metric value, for example it may represent a length or a scale factor
* @param aUnit the unit type in which the metric value is represented
* @param aReferenceTextStyleID can be used to specify a text style in the case of EAlfUnitLine.
*/
IMPORT_C TAlfMetric(TReal32 aMagnitude = 1.f, TInt aUnit = EAlfUnitPixel, TInt aReferenceTextStyleId = EAlfTextStyleNormal) __SOFTFP;
/**
* Constructor. Allows the compiler to pass integers instead of TAlfMetric
* in parameters, in place of pixel metrics.
*
* @param aPixels Number of pixels for the metric.
*/
IMPORT_C TAlfMetric(TInt aPixels);
public:
TReal32 iMagnitude;
/**
* @see TAlfUnit
*/
TInt iUnit;
/**
* @see CAlfTextStyleManager::TextStyle
*/
TInt iReferenceTextStyleId;
};
/**
* A pair of metrics used to represent a value in both X and Y directions, similar to a TAlfRealPoint.
*/
struct TAlfXYMetric
{
public:
/**
* Constructor.
*/
IMPORT_C TAlfXYMetric();
/**
* Constructor. Uses the same metric for both axes.
*
* @param aMetric Metric for the X and Y axes.
*/
IMPORT_C TAlfXYMetric(const TAlfMetric& aMetric);
/**
* Constructor.
*
* @param aX metric for the X axis
* @param aY metric for the Y axis
*/
IMPORT_C TAlfXYMetric(const TAlfMetric& aX, const TAlfMetric& aY);
public:
TAlfMetric iX;
TAlfMetric iY;
};
/**
* Four metrics used to indicate space around the four edges of a rectangle.
* Not called a rectangle because those are typically made up of two XY points,
* while this contains just four edge metrics (named top, bottom, left, and right).
*/
struct TAlfBoxMetric
{
public:
/**
* Constructor.
*/
IMPORT_C TAlfBoxMetric();
/**
* Constructor. Uses the same metric on all sides of the box.
*
* @param aMetric Metric for all sides of the box.
*/
IMPORT_C TAlfBoxMetric(const TAlfMetric& aMetric);
/**
* Constructor. The X metric is used for the left and right sides, and the
* Y metric is used for the top and bottom sides.
*
* @param aMetric Metric for all sides of the box.
*/
IMPORT_C TAlfBoxMetric(const TAlfXYMetric& aMetric);
/**
* Constructor. The top and left edges are specified in a single parameter,
* and the bottom and right edges are also specified in a single parameter.
*
* @param aTopLeft Metrics for the left and top sides.
* @param aBottomRight Metrics for the right and bottom sides.
*/
IMPORT_C TAlfBoxMetric(const TAlfXYMetric& aTopLeft,
const TAlfXYMetric& aBottomRight);
/**
* Constructor.
*
* @param aLeft Metric for the left edge of the box.
* @param aRight Metric for the right edge of the box.
* @param aTop Metric for the top edge of the box.
* @param aBottom Metric for the bottom edge of the box.
*/
IMPORT_C TAlfBoxMetric(const TAlfMetric& aLeft, const TAlfMetric& aRight,
const TAlfMetric& aTop, const TAlfMetric& aBottom);
public:
TAlfMetric iLeft;
TAlfMetric iRight;
TAlfMetric iTop;
TAlfMetric iBottom;
};
#endif // __ALFMETRIC_H__