Class LayoutMap
A LayoutMap maps variable names to layout expression Strings. The FormLayout,
ColumnSpec, and RowSpec parsers expand variables before an encoded layout
specification is parsed and converted into ColumnSpec and RowSpec values.
Variables start with the '$' character. The variable name can be wrapped
by braces ('{' and '}'). For example, you can write:
new FormLayout("pref, $lcg, pref",)
or
new FormLayout("pref, ${lcg}, pref")
.
LayoutMaps build a chain; each LayoutMap has an optional parent map.
The root is defined by getRoot()
. Application-wide
variables should be defined in the root LayoutMap. If you want to override
application-wide variables locally, obtain a LayoutMap using
new LayoutMap()
, configure it, and provide it as argument to the
FormLayout, ColumnSpec, and RowSpec constructors/factory methods.
By default the root LayoutMap provides the following associations:
Variable Name | Abbreviations | Orientation | Description |
label-component-gap | lcg, lcgap | horizontal | gap between a label and its component |
button | b | horizontal | button column with minimum width |
related-gap | rg, rgap | both | gap between two related components |
unrelated-gap | ug, ugap | both | gap between two unrelated components |
line-gap | lg, lgap | vertical | gap between two lines |
narrow-line-gap | nlg, nlgap | vertical | narrow gap between two lines |
paragraph | pg, pgap | vertical | gap between two paragraphs/sections |
Examples:
// Predefined variables new FormLayout( "pref, $lcgap, pref, $rgap, pref", "p, $lgap, p, $lgap, p"); // Custom variables LayoutMap.getRoot().columnPut("half", "39dlu"); LayoutMap.getRoot().columnPut("full", "80dlu"); LayoutMap.getRoot().rowPut("table", "fill:0:grow"); LayoutMap.getRoot().rowPut("table50", "fill:50dlu:grow"); new FormLayout( "pref, $lcgap, $half, 2dlu, $half", "p, $lcgap, $table50"); new FormLayout( "pref, $lcgap, $full", "p, $lcgap, $table50"); // Nested variables LayoutMap.getRoot().columnPut("c-gap-c", "$half, 2dlu, $half"); new FormLayout( "pref, $lcgap, ${c-gap-c}", // -> "pref, $lcgap, $half, 2dlu, $half", "p, $lcgap, $table");LayoutMap holds two internal Maps that associate key Strings with expression Strings for the columns and rows respectively. Null values are not allowed.
Tips:
- You should carefully override predefined variables, because variable users may expect that these don't change.
- Set custom variables in the root LayoutMap.
- Avoid aliases for custom variables.
- Since:
- 1.2
- Version:
- $Revision: 1.18 $
- Author:
- Karsten Lentzsch
- See Also:
-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
columnContainsKey
(String key) Returnstrue
if this map or a parent map - if any - contains a mapping for the specified key.Looks up and returns the String associated with the given key.columnPut
(String key, ColumnSpec value) Associates the specified column String with the specified key in this map.columnRemove
(String key) Removes the column value mapping for this key from this map if it is present.static LayoutMap
getRoot()
Lazily initializes and returns the LayoutMap that is used for variable expansion, if no custom LayoutMap is provided.boolean
rowContainsKey
(String key) Returnstrue
if this map or a parent map - if any - contains a RowSpec mapping for the specified key.Looks up and returns the RowSpec associated with the given key.Associates the specified ColumnSpec with the specified key in this map.Removes the row value mapping for this key from this map if it is present.toString()
Returns a string representation of this LayoutMap that lists the column and row associations.
-
Constructor Details
-
LayoutMap
public LayoutMap()Constructs a LayoutMap that has the root LayoutMap as parent. -
LayoutMap
Constructs a LayoutMap with the given optional parent.- Parameters:
parent
- the parent LayoutMap, may benull
-
-
Method Details
-
getRoot
Lazily initializes and returns the LayoutMap that is used for variable expansion, if no custom LayoutMap is provided.- Returns:
- the LayoutMap that is used, if no custom LayoutMap is provided
-
columnContainsKey
Returnstrue
if this map or a parent map - if any - contains a mapping for the specified key.- Parameters:
key
- key whose presence in this LayoutMap chain is to be tested.- Returns:
true
if this map contains a column mapping for the specified key.- Throws:
NullPointerException
- if the key isnull
.- See Also:
-
columnGet
Looks up and returns the String associated with the given key. First looks for an association in this LayoutMap. If there's no association, the lookup continues with the parent map - if any.- Parameters:
key
- key whose associated value is to be returned.- Returns:
- the column String associated with the
key
, ornull
if no LayoutMap in the parent chain contains an association. - Throws:
NullPointerException
- ifkey
isnull
- See Also:
-
columnPut
Associates the specified column String with the specified key in this map. If the map previously contained a mapping for this key, the old value is replaced by the specified value. The value set in this map overrides an association - if any - in the chain of parent LayoutMaps.The
value
must not benull
. To remove an association from this map usecolumnRemove(String)
.- Parameters:
key
- key with which the specified value is to be associated.value
- column expression value to be associated with the specified key.- Returns:
- previous String associated with specified key,
or
null
if there was no mapping for key. - Throws:
NullPointerException
- if thekey
orvalue
isnull
.- See Also:
-
columnPut
-
columnPut
-
columnRemove
Removes the column value mapping for this key from this map if it is present.Returns the value to which the map previously associated the key, or
null
if the map contained no mapping for this key. The map will not contain a String mapping for the specified key once the call returns.- Parameters:
key
- key whose mapping is to be removed from the map.- Returns:
- previous value associated with specified key, or
null
if there was no mapping for key. - Throws:
NullPointerException
- ifkey
isnull
.- See Also:
-
rowContainsKey
Returnstrue
if this map or a parent map - if any - contains a RowSpec mapping for the specified key.- Parameters:
key
- key whose presence in this LayoutMap chain is to be tested.- Returns:
true
if this map contains a row mapping for the specified key.- Throws:
NullPointerException
- if the key isnull
.- See Also:
-
rowGet
Looks up and returns the RowSpec associated with the given key. First looks for an association in this LayoutMap. If there's no association, the lookup continues with the parent map - if any.- Parameters:
key
- key whose associated value is to be returned.- Returns:
- the row specification associated with the
key
, ornull
if no LayoutMap in the parent chain contains an association. - Throws:
NullPointerException
- ifkey
isnull
- See Also:
-
rowPut
-
rowPut
Associates the specified ColumnSpec with the specified key in this map. If the map previously contained a mapping for this key, the old value is replaced by the specified value. The RowSpec set in this map override an association - if any - in the chain of parent LayoutMaps.The RowSpec must not be
null
. To remove an association from this map userowRemove(String)
.- Parameters:
key
- key with which the specified value is to be associated.value
- ColumnSpec to be associated with the specified key.- Returns:
- previous ColumnSpec associated with specified key,
or
null
if there was no mapping for key. - Throws:
NullPointerException
- if thekey
orvalue
isnull
.- See Also:
-
rowPut
-
rowRemove
Removes the row value mapping for this key from this map if it is present.Returns the value to which the map previously associated the key, or
null
if the map contained no mapping for this key. The map will not contain a String mapping for the specified key once the call returns.- Parameters:
key
- key whose mapping is to be removed from the map.- Returns:
- previous value associated with specified key, or
null
if there was no mapping for key. - Throws:
NullPointerException
- ifkey
isnull
.- See Also:
-
toString
Returns a string representation of this LayoutMap that lists the column and row associations.
-