/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2020 - Raw Material Software Limited
JUCE is an open source library subject to commercial or open-source
licensing.
By using JUCE, you agree to the terms of both the JUCE 6 End-User License
Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
End User License Agreement: www.juce.com/juce-6-licence
Privacy Policy: www.juce.com/juce-privacy-policy
Or: You may also use this code under the terms of the GPL v3 (see
www.gnu.org/licenses).
JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
DISCLAIMED.
==============================================================================
*/
namespace juce
{
/**
Container that handles geometry for grid layouts (fixed columns and rows) using a set of declarative rules.
Implemented from the `CSS Grid Layout` specification as described at:
https://css-tricks.com/snippets/css/complete-guide-grid/
@see GridItem
@tags{GUI}
*/
class JUCE_API Grid final
{
public:
//==============================================================================
/** A size in pixels */
struct Px final
{
explicit Px (float p) : pixels (static_cast<long double>(p)) { /*sta (p >= 0.0f);*/ }
explicit Px (int p) : pixels (static_cast<long double>(p)) { /*sta (p >= 0.0f);*/ }
explicit constexpr Px (long double p) : pixels (p) {}
explicit constexpr Px (unsigned long long p) : pixels (static_cast<long double>(p)) {}
long double pixels;
};
/** A fractional ratio integer */
struct Fr final
{
explicit Fr (int f) : fraction (static_cast<unsigned long long> (f)) {}
explicit constexpr Fr (unsigned long long p) : fraction (p) {}
unsigned long long fraction;
};
//==============================================================================
/** Represents a track. */
struct TrackInfo final
{
/** Creates a track with auto dimension. */
TrackInfo() noexcept;
TrackInfo (Px sizeInPixels) noexcept;
TrackInfo (Fr fractionOfFreeSpace) noexcept;
TrackInfo (Px sizeInPixels, const String& endLineNameToUse) noexcept;
TrackInfo (Fr fractionOfFreeSpace, const String& endLineNameToUse) noexcept;
TrackInfo (const String& startLineNameToUse, Px sizeInPixels) noexcept;
TrackInfo (const String& startLineNameToUse, Fr fractionOfFreeSpace) noexcept;
TrackInfo (const String& startLineNameToUse, Px sizeInPixels, const String& endLineNameToUse) noexcept;
TrackInfo (const String& startLineNameToUse, Fr fractionOfFreeSpace, const String& endLineNameToUse) noexcept;
bool isAuto() const noexcept { return hasKeyword; }
bool isFractional() const noexcept { return isFraction; }
bool isPixels() const noexcept { return ! isFraction; }
const String& getStartLineName() const noexcept { return startLineName; }
const String& getEndLineName() const noexcept { return endLineName; }
/** Get the track's size - which might mean an absolute pixels value or a fractional ratio. */
float getSize() const noexcept { return size; }
private:
friend class Grid;
float getAbsoluteSize (float relativeFractionalUnit) const;
float size = 0; // Either a fraction or an absolute size in pixels
bool isFraction = false;
bool hasKeyword = false;
String startLineName, endLineName;
};
//==============================================================================
/** Possible values for the justifyItems property. */
enum class JustifyItems : int
{
start = 0, /**< Content inside the item is justified towards the left. */
end, /**< Content inside the item is justified towards the right. */
center, /**< Content inside the item is justified towards the center. */
stretch /**< Content inside the item is stretched from left to right. */
};
/** Possible values for the alignItems property. */
enum class AlignItems : int
{
start = 0, /**< Content inside the item is aligned towards the top. */
end, /**< Content inside the item is aligned towards the bottom. */
center, /**< Content inside the item is aligned towards the center. */
stretch /**< Content inside the item is stretched from top to bottom. */
};
/** Possible values for the justifyContent property. */
enum class JustifyContent
{
start, /**< Items are justified towards the left of the container. */
end, /**< Items are justified towards the right of the container. */
center, /**< Items are justified towards the center of the container. */
stretch, /**< Items are stretched from left to right of the container. */
spaceAround, /**< Items are evenly spaced along the row with spaces between them. */
spaceBetween, /**< Items are evenly spaced along the row with spaces around them. */
spaceEvenly /**< Items are evenly spaced along the row with even amount of spaces between them. */
};
/** Possible values for the alignContent property. */
enum class AlignContent
{
start, /**< Items are aligned towards the top of the container. */
end, /**< Items are aligned towards the bottom of the container. */
center, /**< Items are aligned towards the center of the container. */
stretch, /**< Items are stretched from top to bottom of the container. */
spaceAround, /**< Items are evenly spaced along the column with spaces between them. */
spaceBetween, /**< Items are evenly spaced along the column with spaces around them. */
spaceEvenly /**< Items are evenly spaced along the column with even amount of spaces between them. */
};
/** Possible values for the autoFlow property. */
enum class AutoFlow
{
row, /**< Fills the grid by adding rows of items. */
column, /**< Fills the grid by adding columns of items. */
rowDense, /**< Fills the grid by adding rows of items and attempts to fill in gaps. */
columnDense /**< Fills the grid by adding columns of items and attempts to fill in gaps. */
};
//==============================================================================
/** Creates an empty Grid container with default parameters. */
Grid() = default;
/** Destructor */
~Grid() noexcept = default;
//==============================================================================
/** Specifies the alignment of content inside the items along the rows. */
JustifyItems justifyItems = JustifyItems::stretch;
/** Specifies the alignment of content inside the items along the columns. */
AlignItems alignItems = AlignItems::stretch;
/** Specifies the alignment of items along the rows. */
JustifyContent justifyContent = JustifyContent::stretch;
/** Specifies the alignment of items along the columns. */
AlignContent alignContent = AlignContent::stretch;
/** Specifies how the auto-placement algorithm places items. */
AutoFlow autoFlow = AutoFlow::row;
//==============================================================================
/** The set of column tracks to lay out. */
Array<TrackInfo> templateColumns;
/** The set of row tracks to lay out. */
Array<TrackInfo> templateRows;
/** Template areas */
StringArray templateAreas;
/** The row track for auto dimension. */
TrackInfo autoRows;
/** The column track for auto dimension. */
TrackInfo autoColumns;
/** The gap in pixels between columns. */
Px columnGap { 0 };
/** The gap in pixels between rows. */
Px rowGap { 0 };
/** Sets the gap between rows and columns in pixels. */
void setGap (Px sizeInPixels) noexcept { rowGap = columnGap = sizeInPixels; }
//==============================================================================
/** The set of items to lay-out. */
Array<GridItem> items;
//==============================================================================
/** Lays-out the grid's items within the given rectangle. */
void performLayout (Rectangle<int>);
//==============================================================================
/** Returns the number of columns. */
int getNumberOfColumns() const noexcept { return templateColumns.size(); }
/** Returns the number of rows. */
int getNumberOfRows() const noexcept { return templateRows.size(); }
private:
//==============================================================================
struct SizeCalculation;
struct PlacementHelpers;
struct AutoPlacement;
struct BoxAlignment;
};
constexpr Grid::Px operator"" _px (long double px) { return Grid::Px { px }; }
constexpr Grid::Px operator"" _px (unsigned long long px) { return Grid::Px { px }; }
constexpr Grid::Fr operator"" _fr (unsigned long long fr) { return Grid::Fr { fr }; }
} // namespace juce