Package org.eclipse.gef
Class SnapToGeometry
- java.lang.Object
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- org.eclipse.gef.SnapToHelper
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- org.eclipse.gef.SnapToGeometry
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- All Implemented Interfaces:
org.eclipse.draw2d.PositionConstants
public class SnapToGeometry extends SnapToHelper
A temporary helper used to perform snapping to existing elements. This helper can be used in conjunction with theDragEditPartsTracker
when dragging editparts within a graphical viewer. Snapping is based on the existing children of a container. When snapping a rectangle, the edges of the rectangle will snap to edges of other rectangles generated from the children of the given container. Similarly, the centers and middles of rectangles will snap to each other.If the snap request is being made during a Move, Reparent or Resize, then the figures of the participants of that request will not be used for snapping. If the request is a Clone, then the figures for the parts being cloned will be used as possible snap locations.
This helper does not keep up with changes made to the container editpart. Clients should instantiate a new helper each time one is requested and not hold on to instances of the helper.
- Since:
- 3.0
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static class
SnapToGeometry.Entry
A vertical or horizontal snapping point. since 3.0
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Field Summary
Fields Modifier and Type Field Description protected SnapToGeometry.Entry[]
cols
The vertical columnd being snapped to.protected GraphicalEditPart
container
The container editpart providing the coordinates and the children to which snapping occurs.static java.lang.String
KEY_EAST_ANCHOR
The key used to identify the East anchor point in the extended data of a request.static java.lang.String
KEY_NORTH_ANCHOR
The key used to identify the North anchor point in the extended data of a request.static java.lang.String
KEY_SOUTH_ANCHOR
The key used to identify the South anchor point in the extended data of a request.static java.lang.String
KEY_WEST_ANCHOR
The key used to identify the West anchor point in the extended data of a request.static java.lang.String
PROPERTY_SNAP_ENABLED
A property indicating whether this helper should be used.protected SnapToGeometry.Entry[]
rows
The horizontal rows being snapped to.protected static double
THRESHOLD
The sensitivity of the snapping.-
Fields inherited from interface org.eclipse.draw2d.PositionConstants
ALWAYS_LEFT, ALWAYS_RIGHT, BOTTOM, CENTER, EAST, EAST_WEST, HORIZONTAL, LEFT, LEFT_CENTER_RIGHT, MIDDLE, NONE, NORTH, NORTH_EAST, NORTH_SOUTH, NORTH_WEST, NSEW, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TOP_MIDDLE_BOTTOM, VERTICAL, WEST
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Constructor Summary
Constructors Constructor Description SnapToGeometry(GraphicalEditPart container)
Constructs a helper that will use the given part as its basis for snapping.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected java.util.List
generateSnapPartsList(java.util.List exclusions)
Generates a list of parts which should be snapped to.protected double
getCorrectionFor(SnapToGeometry.Entry[] entries, java.util.Map extendedData, boolean vert, double near, double far)
Returns the correction value for the given entries and sides.protected double
getCorrectionFor(SnapToGeometry.Entry[] entries, java.util.Map extendedData, boolean vert, double value, int side)
Returns the correction value between +/-getThreshold()
, or the #getThreshold () if no corrections were found.protected org.eclipse.draw2d.geometry.Rectangle
getFigureBounds(GraphicalEditPart part)
Returns the rectangular contribution for the given editpart.protected double
getThreshold()
Get the sensitivity of the snapping.protected void
populateRowsAndCols(java.util.List parts)
Updates the cached row and column Entries using the provided parts.protected void
setThreshold(double newThreshold)
Set the sensitivity of the snapping.int
snapRectangle(Request request, int snapOrientation, org.eclipse.draw2d.geometry.PrecisionRectangle baseRect, org.eclipse.draw2d.geometry.PrecisionRectangle result)
Applies a snap correction to a Rectangle based on a given Rectangle.-
Methods inherited from class org.eclipse.gef.SnapToHelper
makeAbsolute, makeRelative, snapPoint, snapPoint, snapRectangle
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Field Detail
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PROPERTY_SNAP_ENABLED
public static final java.lang.String PROPERTY_SNAP_ENABLED
A property indicating whether this helper should be used. The value should be an instance of Boolean. Currently, this class does not check to see if the viewer property is set totrue
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KEY_NORTH_ANCHOR
public static final java.lang.String KEY_NORTH_ANCHOR
The key used to identify the North anchor point in the extended data of a request. The north anchor may be set to anInteger
value indicating where the snapping is occurring. This is used for feedback purposes.- See Also:
- Constant Field Values
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KEY_SOUTH_ANCHOR
public static final java.lang.String KEY_SOUTH_ANCHOR
The key used to identify the South anchor point in the extended data of a request. The south anchor may be set to anInteger
value indicating where the snapping is occurring. This is used for feedback purposes.- See Also:
- Constant Field Values
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KEY_WEST_ANCHOR
public static final java.lang.String KEY_WEST_ANCHOR
The key used to identify the West anchor point in the extended data of a request. The west anchor may be set to anInteger
value indicating where the snapping is occurring. This is used for feedback purposes.- See Also:
- Constant Field Values
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KEY_EAST_ANCHOR
public static final java.lang.String KEY_EAST_ANCHOR
The key used to identify the East anchor point in the extended data of a request. The east anchor may be set to anInteger
value indicating where the snapping is occurring. This is used for feedback purposes.- See Also:
- Constant Field Values
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THRESHOLD
protected static final double THRESHOLD
The sensitivity of the snapping. Corrections greater than this value will not occur.- See Also:
- Constant Field Values
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rows
protected SnapToGeometry.Entry[] rows
The horizontal rows being snapped to.
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cols
protected SnapToGeometry.Entry[] cols
The vertical columnd being snapped to.
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container
protected GraphicalEditPart container
The container editpart providing the coordinates and the children to which snapping occurs.
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Constructor Detail
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SnapToGeometry
public SnapToGeometry(GraphicalEditPart container)
Constructs a helper that will use the given part as its basis for snapping. The part's contents pane will provide the coordinate system and its children determine the existing elements.- Parameters:
container
- the container editpart- Since:
- 3.0
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Method Detail
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getThreshold
protected double getThreshold()
Get the sensitivity of the snapping. Corrections greater than this value will not occur.- Returns:
- the snapping threshold
- Since:
- 3.4
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setThreshold
protected void setThreshold(double newThreshold)
Set the sensitivity of the snapping.- Parameters:
newThreshold
- the new snapping threshold- Since:
- 3.4
- See Also:
getThreshold()
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generateSnapPartsList
protected java.util.List generateSnapPartsList(java.util.List exclusions)
Generates a list of parts which should be snapped to. The list is the original children, minus the given exclusions, minus and children whose figures are not visible.- Parameters:
exclusions
- the children to exclude- Returns:
- a list of parts which should be snapped to
- Since:
- 3.0
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getCorrectionFor
protected double getCorrectionFor(SnapToGeometry.Entry[] entries, java.util.Map extendedData, boolean vert, double near, double far)
Returns the correction value for the given entries and sides. During a move, the left, right, or center is free to snap to a location.- Parameters:
entries
- the entriesextendedData
- the requests extended datavert
-true
if the correction is verticalnear
- the left/top side of the rectanglefar
- the right/bottom side of the rectangle- Returns:
- the correction amount or #getThreshold () if no correction was made
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getCorrectionFor
protected double getCorrectionFor(SnapToGeometry.Entry[] entries, java.util.Map extendedData, boolean vert, double value, int side)
Returns the correction value between +/-getThreshold()
, or the #getThreshold () if no corrections were found.- Parameters:
entries
- the entriesextendedData
- the map for setting valuesvert
-true
if verticalvalue
- the value being correctedside
- which sides should be considered- Returns:
- the correction or #getThreshold () if no correction was made
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getFigureBounds
protected org.eclipse.draw2d.geometry.Rectangle getFigureBounds(GraphicalEditPart part)
Returns the rectangular contribution for the given editpart. This is the rectangle with which snapping is performed.- Parameters:
part
- the child- Returns:
- the rectangular guide for that part
- Since:
- 3.0
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populateRowsAndCols
protected void populateRowsAndCols(java.util.List parts)
Updates the cached row and column Entries using the provided parts.- Parameters:
parts
- a List of EditParts- Since:
- 3.0
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snapRectangle
public int snapRectangle(Request request, int snapOrientation, org.eclipse.draw2d.geometry.PrecisionRectangle baseRect, org.eclipse.draw2d.geometry.PrecisionRectangle result)
Description copied from class:SnapToHelper
Applies a snap correction to a Rectangle based on a given Rectangle. The provided baseRect will be used as a reference for snapping. The types of snapping to be performed are indicated by the snapOrientation parameter. The correction is applied to the result field.The baseRect is not modified. The correction is applied to the result. The request's
extended data
may contain additional information about the snapping which was performed.All coordinate information received and returned by this method should be in absolute coordinates.
- Specified by:
snapRectangle
in classSnapToHelper
- Parameters:
request
- the request ornull
snapOrientation
- the input snap locationsbaseRect
- the input rectangleresult
- the correction is applied to this rectangle- Returns:
- the remaining snap locations
- See Also:
SnapToHelper.snapRectangle(Request, int, PrecisionRectangle, PrecisionRectangle)
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