IT. Expert System.

Java Standard Edition (SE)

BoxView


javax.swing.text

Class BoxView

  • All Implemented Interfaces:
    SwingConstants
    Direct Known Subclasses:
    BlockView, FlowView, TableView, TableView.TableCell, TableView.TableRow, WrappedPlainView, ZoneView


    public class BoxView
    extends CompositeView
    A view that arranges its children into a box shape by tiling its children along an axis. The box is somewhat like that found in TeX where there is alignment of the children, flexibility of the children is considered, etc. This is a building block that might be useful to represent things like a collection of lines, paragraphs, lists, columns, pages, etc. The axis along which the children are tiled is considered the major axis. The orthogonal axis is the minor axis.

    Layout for each axis is handled separately by the methods layoutMajorAxis and layoutMinorAxis. Subclasses can change the layout algorithm by reimplementing these methods. These methods will be called as necessary depending upon whether or not there is cached layout information and the cache is considered valid. These methods are typically called if the given size along the axis changes, or if layoutChanged is called to force an updated layout. The layoutChanged method invalidates cached layout information, if there is any. The requirements published to the parent view are calculated by the methods calculateMajorAxisRequirements and calculateMinorAxisRequirements. If the layout algorithm is changed, these methods will likely need to be reimplemented.

    • Constructor Detail

      • BoxView

        public BoxView(Element elem,
                       int axis)
        Constructs a BoxView.
        Parameters:
        elem - the element this view is responsible for
        axis - either View.X_AXIS or View.Y_AXIS
    • Method Detail

      • getAxis

        public int getAxis()
        Fetches the tile axis property. This is the axis along which the child views are tiled.
        Returns:
        the major axis of the box, either View.X_AXIS or View.Y_AXIS
        Since:
        1.3
      • setAxis

        public void setAxis(int axis)
        Sets the tile axis property. This is the axis along which the child views are tiled.
        Parameters:
        axis - either View.X_AXIS or View.Y_AXIS
        Since:
        1.3
      • layoutChanged

        public void layoutChanged(int axis)
        Invalidates the layout along an axis. This happens automatically if the preferences have changed for any of the child views. In some cases the layout may need to be recalculated when the preferences have not changed. The layout can be marked as invalid by calling this method. The layout will be updated the next time the setSize method is called on this view (typically in paint).
        Parameters:
        axis - either View.X_AXIS or View.Y_AXIS
        Since:
        1.3
      • isLayoutValid

        protected boolean isLayoutValid(int axis)
        Determines if the layout is valid along the given axis.
        Parameters:
        axis - either View.X_AXIS or View.Y_AXIS
        Since:
        1.4
      • paintChild

        protected void paintChild(Graphics g,
                                  Rectangle alloc,
                                  int index)
        Paints a child. By default that is all it does, but a subclass can use this to paint things relative to the child.
        Parameters:
        g - the graphics context
        alloc - the allocated region to paint into
        index - the child index, >= 0 && < getViewCount()
      • replace

        public void replace(int index,
                            int length,
                            View[] elems)
        Invalidates the layout and resizes the cache of requests/allocations. The child allocations can still be accessed for the old layout, but the new children will have an offset and span of 0.
        Overrides:
        replace in class CompositeView
        Parameters:
        index - the starting index into the child views to insert the new views; this should be a value >= 0 and <= getViewCount
        length - the number of existing child views to remove; This should be a value >= 0 and <= (getViewCount() - offset)
        elems - the child views to add; this value can be nullto indicate no children are being added (useful to remove)
      • preferenceChanged

        public void preferenceChanged(View child,
                                      boolean width,
                                      boolean height)
        This is called by a child to indicate its preferred span has changed. This is implemented to throw away cached layout information so that new calculations will be done the next time the children need an allocation.
        Overrides:
        preferenceChanged in class View
        Parameters:
        child - the child view
        width - true if the width preference should change
        height - true if the height preference should change
        See Also:
        JComponent.revalidate()
      • getResizeWeight

        public int getResizeWeight(int axis)
        Gets the resize weight. A value of 0 or less is not resizable.
        Overrides:
        getResizeWeight in class View
        Parameters:
        axis - may be either View.X_AXIS or View.Y_AXIS
        Returns:
        the weight
        Throws:
        IllegalArgumentException - for an invalid axis
      • setSize

        public void setSize(float width,
                            float height)
        Sets the size of the view. This should cause layout of the view if the view caches any layout information. This is implemented to call the layout method with the sizes inside of the insets.
        Overrides:
        setSize in class View
        Parameters:
        width - the width >= 0
        height - the height >= 0
      • paint

        public void paint(Graphics g,
                          Shape allocation)
        Renders the BoxView using the given rendering surface and area on that surface. Only the children that intersect the clip bounds of the given Graphics will be rendered.
        Specified by:
        paint in class View
        Parameters:
        g - the rendering surface to use
        allocation - the allocated region to render into
        See Also:
        View.paint(java.awt.Graphics, java.awt.Shape)
      • getChildAllocation

        public Shape getChildAllocation(int index,
                                        Shape a)
        Fetches the allocation for the given child view. This enables finding out where various views are located. This is implemented to return null if the layout is invalid, otherwise the superclass behavior is executed.
        Overrides:
        getChildAllocation in class CompositeView
        Parameters:
        index - the index of the child, >= 0 && > getViewCount()
        a - the allocation to this view
        Returns:
        the allocation to the child; or null if a is null; or null if the layout is invalid
      • viewToModel

        public int viewToModel(float x,
                               float y,
                               Shape a,
                               Position.Bias[] bias)
        Provides a mapping from the view coordinate space to the logical coordinate space of the model.
        Overrides:
        viewToModel in class CompositeView
        Parameters:
        x - x coordinate of the view location to convert >= 0
        y - y coordinate of the view location to convert >= 0
        a - the allocated region to render into
        bias - either Position.Bias.Forward or Position.Bias.Backward
        Returns:
        the location within the model that best represents the given point in the view >= 0
        See Also:
        View.viewToModel(float, float, java.awt.Shape, javax.swing.text.Position.Bias[])
      • getAlignment

        public float getAlignment(int axis)
        Determines the desired alignment for this view along an axis. This is implemented to give the total alignment needed to position the children with the alignment points lined up along the axis orthogonal to the axis that is being tiled. The axis being tiled will request to be centered (i.e. 0.5f).
        Overrides:
        getAlignment in class View
        Parameters:
        axis - may be either View.X_AXIS or View.Y_AXIS
        Returns:
        the desired alignment >= 0.0f && <= 1.0f; this should be a value between 0.0 and 1.0 where 0 indicates alignment at the origin and 1.0 indicates alignment to the full span away from the origin; an alignment of 0.5 would be the center of the view
        Throws:
        IllegalArgumentException - for an invalid axis
      • getPreferredSpan

        public float getPreferredSpan(int axis)
        Determines the preferred span for this view along an axis.
        Specified by:
        getPreferredSpan in class View
        Parameters:
        axis - may be either View.X_AXIS or View.Y_AXIS
        Returns:
        the span the view would like to be rendered into >= 0; typically the view is told to render into the span that is returned, although there is no guarantee; the parent may choose to resize or break the view
        Throws:
        IllegalArgumentException - for an invalid axis type
        See Also:
        View.getPreferredSpan(int)
      • getMinimumSpan

        public float getMinimumSpan(int axis)
        Determines the minimum span for this view along an axis.
        Overrides:
        getMinimumSpan in class View
        Parameters:
        axis - may be either View.X_AXIS or View.Y_AXIS
        Returns:
        the span the view would like to be rendered into >= 0; typically the view is told to render into the span that is returned, although there is no guarantee; the parent may choose to resize or break the view
        Throws:
        IllegalArgumentException - for an invalid axis type
        See Also:
        View.getPreferredSpan(int)
      • getMaximumSpan

        public float getMaximumSpan(int axis)
        Determines the maximum span for this view along an axis.
        Overrides:
        getMaximumSpan in class View
        Parameters:
        axis - may be either View.X_AXIS or View.Y_AXIS
        Returns:
        the span the view would like to be rendered into >= 0; typically the view is told to render into the span that is returned, although there is no guarantee; the parent may choose to resize or break the view
        Throws:
        IllegalArgumentException - for an invalid axis type
        See Also:
        View.getPreferredSpan(int)
      • isAllocationValid

        protected boolean isAllocationValid()
        Are the allocations for the children still valid?
        Returns:
        true if allocations still valid
      • isBefore

        protected boolean isBefore(int x,
                                   int y,
                                   Rectangle innerAlloc)
        Determines if a point falls before an allocated region.
        Specified by:
        isBefore in class CompositeView
        Parameters:
        x - the X coordinate >= 0
        y - the Y coordinate >= 0
        innerAlloc - the allocated region; this is the area inside of the insets
        Returns:
        true if the point lies before the region else false
      • isAfter

        protected boolean isAfter(int x,
                                  int y,
                                  Rectangle innerAlloc)
        Determines if a point falls after an allocated region.
        Specified by:
        isAfter in class CompositeView
        Parameters:
        x - the X coordinate >= 0
        y - the Y coordinate >= 0
        innerAlloc - the allocated region; this is the area inside of the insets
        Returns:
        true if the point lies after the region else false
      • getViewAtPoint

        protected View getViewAtPoint(int x,
                                      int y,
                                      Rectangle alloc)
        Fetches the child view at the given coordinates.
        Specified by:
        getViewAtPoint in class CompositeView
        Parameters:
        x - the X coordinate >= 0
        y - the Y coordinate >= 0
        alloc - the parents inner allocation on entry, which should be changed to the child's allocation on exit
        Returns:
        the view
      • childAllocation

        protected void childAllocation(int index,
                                       Rectangle alloc)
        Allocates a region for a child view.
        Specified by:
        childAllocation in class CompositeView
        Parameters:
        index - the index of the child view to allocate, >= 0 && < getViewCount()
        alloc - the allocated region
      • layout

        protected void layout(int width,
                              int height)
        Perform layout on the box
        Parameters:
        width - the width (inside of the insets) >= 0
        height - the height (inside of the insets) >= 0
      • getWidth

        public int getWidth()
        Returns the current width of the box. This is the width that it was last allocated.
        Returns:
        the current width of the box
      • getHeight

        public int getHeight()
        Returns the current height of the box. This is the height that it was last allocated.
        Returns:
        the current height of the box
      • layoutMajorAxis

        protected void layoutMajorAxis(int targetSpan,
                                       int axis,
                                       int[] offsets,
                                       int[] spans)
        Performs layout for the major axis of the box (i.e. the axis that it represents). The results of the layout (the offset and span for each children) are placed in the given arrays which represent the allocations to the children along the major axis.
        Parameters:
        targetSpan - the total span given to the view, which would be used to layout the children
        axis - the axis being layed out
        offsets - the offsets from the origin of the view for each of the child views; this is a return value and is filled in by the implementation of this method
        spans - the span of each child view; this is a return value and is filled in by the implementation of this method
      • layoutMinorAxis

        protected void layoutMinorAxis(int targetSpan,
                                       int axis,
                                       int[] offsets,
                                       int[] spans)
        Performs layout for the minor axis of the box (i.e. the axis orthogonal to the axis that it represents). The results of the layout (the offset and span for each children) are placed in the given arrays which represent the allocations to the children along the minor axis.
        Parameters:
        targetSpan - the total span given to the view, which would be used to layout the children
        axis - the axis being layed out
        offsets - the offsets from the origin of the view for each of the child views; this is a return value and is filled in by the implementation of this method
        spans - the span of each child view; this is a return value and is filled in by the implementation of this method
      • calculateMajorAxisRequirements

        protected SizeRequirements calculateMajorAxisRequirements(int axis,
                                                                  SizeRequirements r)
        Calculates the size requirements for the major axis axis.
        Parameters:
        axis - the axis being studied
        r - the SizeRequirements object; if null one will be created
        Returns:
        the newly initialized SizeRequirements object
        See Also:
        SizeRequirements
      • calculateMinorAxisRequirements

        protected SizeRequirements calculateMinorAxisRequirements(int axis,
                                                                  SizeRequirements r)
        Calculates the size requirements for the minor axis axis.
        Parameters:
        axis - the axis being studied
        r - the SizeRequirements object; if null one will be created
        Returns:
        the newly initialized SizeRequirements object
        See Also:
        SizeRequirements
      • baselineLayout

        protected void baselineLayout(int targetSpan,
                                      int axis,
                                      int[] offsets,
                                      int[] spans)
        Computes the location and extent of each child view in this BoxView given the targetSpan, which is the width (or height) of the region we have to work with.
        Parameters:
        targetSpan - the total span given to the view, which would be used to layout the children
        axis - the axis being studied, either View.X_AXIS or View.Y_AXIS
        offsets - an empty array filled by this method with values specifying the location of each child view
        spans - an empty array filled by this method with values specifying the extent of each child view
      • baselineRequirements

        protected SizeRequirements baselineRequirements(int axis,
                                                        SizeRequirements r)
        Calculates the size requirements for this BoxView by examining the size of each child view.
        Parameters:
        axis - the axis being studied
        r - the SizeRequirements object; if null one will be created
        Returns:
        the newly initialized SizeRequirements object
      • getOffset

        protected int getOffset(int axis,
                                int childIndex)
        Fetches the offset of a particular child's current layout.
        Parameters:
        axis - the axis being studied
        childIndex - the index of the requested child
        Returns:
        the offset (location) for the specified child
      • getSpan

        protected int getSpan(int axis,
                              int childIndex)
        Fetches the span of a particular child's current layout.
        Parameters:
        axis - the axis being studied
        childIndex - the index of the requested child
        Returns:
        the span (width or height) of the specified child
      • flipEastAndWestAtEnds

        protected boolean flipEastAndWestAtEnds(int position,
                                                Position.Bias bias)
        Determines in which direction the next view lays. Consider the View at index n. Typically the Views are layed out from left to right, so that the View to the EAST will be at index n + 1, and the View to the WEST will be at index n - 1. In certain situations, such as with bidirectional text, it is possible that the View to EAST is not at index n + 1, but rather at index n - 1, or that the View to the WEST is not at index n - 1, but index n + 1. In this case this method would return true, indicating the Views are layed out in descending order. Otherwise the method would return false indicating the Views are layed out in ascending order.

        If the receiver is laying its Views along the Y_AXIS, this will will return the value from invoking the same method on the View responsible for rendering position and bias. Otherwise this will return false.

        Overrides:
        flipEastAndWestAtEnds in class CompositeView
        Parameters:
        position - position into the model
        bias - either Position.Bias.Forward or Position.Bias.Backward
        Returns:
        true if the Views surrounding the View responding for rendering position and bias are layed out in descending order; otherwise false


Content

Android Reference

Java basics

Java Enterprise Edition (EE)

Java Standard Edition (SE)

SQL

HTML

PHP

CSS

Java Script

MYSQL

JQUERY

VBS

REGEX

C

C++

C#

Design patterns

RFC (standard status)

RFC (proposed standard status)

RFC (draft standard status)

RFC (informational status)

RFC (experimental status)

RFC (best current practice status)

RFC (historic status)

RFC (unknown status)

IT dictionary

License.
All information of this service is derived from the free sources and is provided solely in the form of quotations. This service provides information and interfaces solely for the familiarization (not ownership) and under the "as is" condition.
Copyright 2016 © ELTASK.COM. All rights reserved.
Site is optimized for mobile devices.
Downloads: 266 / 158872151. Delta: 0.05664 с