haiku/docs/user/interface/TwoDimensionalLayout.dox

/*
 * Copyright 2010, Haiku, Inc. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 *
 * Documentation by:
 *   Alex Wilson <yourpalal2@gmail.com>
 * Corresponds to:
 *   /trunk/headers/os/interface/TwoDimensionalLayout.h  rev 38207
 *   /trunk/src/kits/interface/TwoDimensionalLayout.cpp  rev 38207
 */


/*!
	\file TwoDimensionalLayout.h
	\brief Defines the BTwoDimensionalLayout class.
*/


/*!
	\class BTwoDimensionalLayout
	\ingroup interface
	\ingroup layout
	\ingroup libbe

	\brief Abstract BLayout subclass arranging items within rows and columns.

	This class manages all the tricky work of actually positioning/resizing
	items, as well as calculating size constraints and providing extra features,
	such as spacing/insets and alignment of multiple
	BTwoDimensionalLayout&apos;s. Derived classes need only implement a few hook
	methods to get a working layout.

	\warning This class is not yet finalized, if you use it in your software
	assume that it will break some time in the future.
*/


/*!
	\struct BTwoDimensionalLayout::ColumnRowConstraints
	\brief Used by BTwoDimensionalLayout derived classes to communicate the
		size constraints for a given column or row to the 
		BTwoDimensionalLayout class.
*/


/*!
	\struct BTwoDimensionalLayout::Dimensions
	\brief Used by BTwoDimensionalLayout derived classes to communicate the
		positioning and size of a BLayoutItem, in terms of columns and rows to
		the BTwoDimensionalLayout class.
*/


/*!
	\fn void BTwoDimensionalLayout::AlignLayoutWith(
		BTwoDimensionalLayout* other, enum orientation orientation)
	\brief Align the BLayoutItem&apos;s in the specified \a orientation within
		two or more BTwoDimensionalLayout&apos;s.

	When two (or more) BTwoDimensionalLayout&apos;s are aligned within a
	certain \a orientation, then the BLayoutItem&apos;s within those
	BTwoDimensionalLayout&apos;s will have identical widths or heights
	(depending on how the BTwoDimensionalLayout&apos;s are aligned.)

	If you align two BGroupLayout&apos;s horizontally for example, then the
	BLayoutItem at index 0 in both BGroupLayout&apos;s will be given the same
	horizontal area. The same is true for the BLayoutItem at index 1,
	2, etc. Not all BTwoDimensionalLayout&apos;s have to have an item at each
	index for the alignment to proceed.

	\param other The BTwoDimensionalLayout to be aligned with.
	\param orientation The \a orientation on which to be aligned.
*/


/*!
	\fn void BTwoDimensionalLayout::SetInsets(float left, float top,
		float right, float bottom)
	\brief Set the insets for this BTwoDimensionalLayout (in pixels).

	Set the spacing around the edges of this BTwoDimensionalLayout. If you
	pass \c B_USE_DEFAULT_SPACING for a certain parameter, that parameter will
	be replaced with the value returned by BControlLook::DefaultItemSpacing().

	\see BTwoDimensionalLayout::GetInsets();
*/


/*!
	\fn void BTwoDimensionalLayout::GetInsets(float* left, float* top,
		float* right, float* bottom) const
	\brief Get the insets for the BTwoDimensionalLayout (in pixels).

	Passing \c NULL for any parameter is not an error, those parameters will
	be ignored.

	\see BTwoDimensionalLayout::SetInsets();
*/


/*!
	\name BTwoDimensionalLayout Hook methods

	These methods are called automatically as needed during layout, and
	provide the BTwoDimensionalLayout class with the necessary information
	to properly layout the BLayoutItem in this BTwoDimensionalLayout.
*/


//! @{


/*!
	\fn void BTwoDimensionalLayout::PrepareItems(enum orientation orientation)
	\brief Prepare the BLayoutItem in this BTwoDimensionalLayout subclass
		for layout within a certain \a orientation.

	This is a good place to update cache information that will be used in
	other hook methods, for example.
*/


/*!
	\fn bool BTwoDimensionalLayout::HasMultiColumnItems()
	\brief Tests whether or not this BTwoDimensionalLayout contains any
		BLayoutItem&apos;s spanning more than one column.

	The BTwoDimensionalLayout implementation returns false.
*/


/*!
	\fn bool BTwoDimensionalLayout::HasMultiRowItems()
	\brief Tests whether or not this BTwoDimensionalLayout contains any
		BLayoutItem&apos;s spanning more than one row.

	The BTwoDimensionalLayout implementation returns false.
*/


/*!
	\fn int32 BTwoDimensionalLayout::InternalCountColumns()
	\brief Get the number of columns in the BTwoDimensionalLayout.

	\returns The number of columns in the BTwoDimensionalLayout.
*/


/*!
	\fn int32 BTwoDimensionalLayout::InternalCountRows()
	\brief Get the number of rows in the BTwoDimensionalLayout.

	\returns The number of rows in the BTwoDimensionalLayout.
*/


/*!
	\fn void BTwoDimensionalLayout::GetColumnRowConstraints(enum orientation 
		orientation, int32 index, ColumnRowConstraints* constraints)
	\brief Fill in the ColumnRowConstraints for a certain column or row in
		the BTwoDimensionalLayout.

	This method is used to communicate the size constraints and weight for
	a given row/column in the BTwoDimensionalLayout.
*/


/*!
	\fn void BTwoDimensionalLayout::GetItemDimensions(BLayoutItem* item,
		Dimensions* dimensions)
	\brief Tell the base class what column and row a BLayoutItem is in as
		well as how many columns and rows it covers.
*/


//! @}