com.inet.html.views.layouts
Class StackManager

java.lang.Object
  com.inet.html.views.layouts.StackManager

public class StackManager
extends java.lang.Object

This class gathers all informations about floats on a site. It helps to find wrapping edges and new line positions. Here's a list of rules, which have to be fulfilled by floats and flowing content. (This list is not equal to the spec, it's was generated by observing the Gecko 1.9 Behavior) - A flow-line will be terminated if it hits a float-right - A flow-line will start after a flow-left( except if there's an earlier flow-right, than it starts at the beginning of the box and ends at the flow-right) - All floats generated in a flow-line will be placed AFTER the end of this line(the end means: end of the box, flow-content on the next line, ...) --> A float cannot influence the content layouted before this float! - A higher position is better than a position more to the left or the the right - A float cannot be placed higher than any float generated before - Absolute- or Float-Blocks are the root for their inner floats! - if the parent has no size yet, all sub-floats are layouted like inline-blocks and taken out of the flow after any boundary is reached(this case is really hard to control) - if there is any limit given by the parent the floats try to limit ther width to this size What this Class needs to place a new line: - current box position and width - minimum y to start searching - minimum width to place the content(there's no sense in placing a new line which is to small to hold content) When to notify this class(add floats an start placing them)? - Generating a new float - Starting a box - Start of a new line When to query this class(get lines respecting the floats)? - Start of a new line - Adding content which changes the baseline/height of a line Remember: Floats are boxes with a predefined Width. They do not belong to the text flow but will influence it. Float-positions are unique among it's absolute parent's space. Floats can never overlap except by using negative margins!

Nested Class Summary

static class

StackManager.LineSpaceInfo The LineSpaceInfo contains all informations, which are required to place a new line or a snippet of content.

Field Summary

static byte	CLEAR_BOTH Request the StackManager to fetch the top-most position for the current element, where is no float on either side
static byte	CLEAR_LEFT Request the StackManager to fetch the top-most position for the current element, where is no float to the left
static byte	CLEAR_NONE Request the StackManager to fetch the top-most position for the current element
static byte	CLEAR_RIGHT Request the StackManager to fetch the top-most position for the current element, where is no float to the rigth
static int	MODE_ALL_NON_NEGATIVE internal mode to iterate over all elements in this stack manager
static int	MODE_FLOATING Constant to address all floats and absolute positioned views with auto z-index
static int	MODE_NEGATIVE Constant to address all absolute positioned views with negative z-index
static int	MODE_NEUTRAL Constant to address all absolute positioned views unset z-index, ignored on paint, used on getSpan
static int	MODE_POSITIVE Constant to address all absolute positioned views with positive z-index

Constructor Summary

StackManager(BoxView root)
Creates a float manager bound to a root block element

Method Summary

void	addView(BoxView box, BlockView outerBox, int topY) Adds a new float
void	addView(BoxView box, BlockView outerBox, int x, int y) Adds a position relative.
void	clear() Removes all known float informations
void	clearMyFloats(BoxView parent) Removes all floats with parent set as their parent.
StackManager.LineSpaceInfo	findClearSpace(java.awt.Rectangle minRequired, java.awt.Rectangle bounds, int clear, int textAlign) Tries to find a position, where there is enough room to place the content.
StackManager.LineSpaceInfo	findLineSpace(java.awt.Rectangle minRequired, java.awt.Rectangle bounds, int clear, int textAlign) Tries to find a position, where there is enough room to place the content.
int	getAvailableVSpace(int y, int leftX, int rightX) Returns the available vertical space within the selected bounds
int	getBottomPosition(BlockView parent) The difference between the top of the root-View and the bottom of the lowest float in pixel.
com.inet.html.views.layouts.StackManager.PositionInfo	getNextFloatBelow(int y, int leftX, int rightX, boolean typeleft) Tries to find the next lower float of the requested type
java.awt.Point	getPositionInfo(BoxView child) Tries to find the location information about a child.
java.awt.Rectangle	getSpan() Returns the maximum span in positive direction of the floats handled by this manager
java.awt.Rectangle	getSpan(int mode) Returns the span of a stack group
ViewPositionInfo	getViewForPosition(java.awt.Point position, java.awt.Rectangle a, int mode) Finds the view and it's location for a specific point of the screen
boolean	hasViews() Returns the number of floats currently managed by this instance
java.awt.Shape	modelToView(int pos, java.awt.Shape a, javax.swing.text.Position.Bias b, int mode) Tries to resolve a model offset to a screen location
void	notifyBlockFinished(boolean hard) Notifies the manager, that the containing block, which holds this manager, has finished layouting.
void	notifyNewLine(float topY) placed the recently added floats
void	paint(java.awt.Graphics g, java.awt.Shape allocation, int mode) Paint the Blocks of this manager
int	viewToModel(float x, float y, java.awt.Shape a, javax.swing.text.Position.Bias[] biasReturn, int mode) Tries to resolve a position to a model offset

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CLEAR_NONE

public static final byte CLEAR_NONE

Request the StackManager to fetch the top-most position for the current element

See Also:

Constant Field Values

CLEAR_LEFT

public static final byte CLEAR_LEFT

Request the StackManager to fetch the top-most position for the current element, where is no float to the left

See Also:

Constant Field Values

CLEAR_RIGHT

public static final byte CLEAR_RIGHT

Request the StackManager to fetch the top-most position for the current element, where is no float to the rigth

See Also:

Constant Field Values

CLEAR_BOTH

public static final byte CLEAR_BOTH

Request the StackManager to fetch the top-most position for the current element, where is no float on either side

See Also:

Constant Field Values

MODE_NEGATIVE

public static final int MODE_NEGATIVE

Constant to address all absolute positioned views with negative z-index

See Also:

Constant Field Values

MODE_FLOATING

public static final int MODE_FLOATING

Constant to address all floats and absolute positioned views with auto z-index

See Also:

Constant Field Values

MODE_NEUTRAL

public static final int MODE_NEUTRAL

Constant to address all absolute positioned views unset z-index, ignored on paint, used on getSpan

See Also:

Constant Field Values

MODE_POSITIVE

public static final int MODE_POSITIVE

Constant to address all absolute positioned views with positive z-index

See Also:

Constant Field Values

MODE_ALL_NON_NEGATIVE

public static final int MODE_ALL_NON_NEGATIVE

internal mode to iterate over all elements in this stack manager

See Also:

Constant Field Values

Constructor Detail

StackManager

public StackManager(BoxView root)

Creates a float manager bound to a root block element

Parameters:

root - the root block element

Method Detail

getPositionInfo

public java.awt.Point getPositionInfo(BoxView child)

Tries to find the location information about a child.

Parameters:

child - the child to search for

Returns:

the location information or null

addView

public void addView(BoxView box,
                    BlockView outerBox,
                    int topY)

Adds a new float

Parameters:

box - new floating box

outerBox - parent of this float

topY - the highest position this float may have

addView

public void addView(BoxView box,
                    BlockView outerBox,
                    int x,
                    int y)

Adds a position relative. Required to handle the paint order correctly

Parameters:

box - new floating box

outerBox - parent of this float

x - the layouted position of the element

y - the layouted position of the element

paint

public void paint(java.awt.Graphics g,
                  java.awt.Shape allocation,
                  int mode)

Paint the Blocks of this manager

Parameters:

g - the graphics to pain to

allocation - the location to draw at

mode - the part of the views, which have to be painted

See Also:

MODE_NEGATIVE, MODE_FLOATING, MODE_POSITIVE

viewToModel

public int viewToModel(float x,
                       float y,
                       java.awt.Shape a,
                       javax.swing.text.Position.Bias[] biasReturn,
                       int mode)

Tries to resolve a position to a model offset

Parameters:

x - the x coordinate

y - the y coordinate

a - the shape to search in

biasReturn - the direction of the returned offset

mode - the mode constant to address a certain stack group

Returns:

the model offset

See Also:

MODE_NEGATIVE, MODE_FLOATING, MODE_NEUTRAL, MODE_POSITIVE

modelToView

public java.awt.Shape modelToView(int pos,
                                  java.awt.Shape a,
                                  javax.swing.text.Position.Bias b,
                                  int mode)
                           throws javax.swing.text.BadLocationException

Tries to resolve a model offset to a screen location

Parameters:

pos - the model offset

a - the shape to place the location into

b - the caret direction

mode - the mode constant to address a certain stack group

Returns:

the bounds of the box at this offset or null

Throws:

javax.swing.text.BadLocationException - thrown if there are model errors

See Also:

MODE_NEGATIVE, MODE_FLOATING, MODE_NEUTRAL, MODE_POSITIVE

getNextFloatBelow

public com.inet.html.views.layouts.StackManager.PositionInfo getNextFloatBelow(int y,
                                                                               int leftX,
                                                                               int rightX,
                                                                               boolean typeleft)

Tries to find the next lower float of the requested type

Parameters:

y - Y index to start from

leftX - Left border of the space to search

rightX - Right border of the space to search

typeleft - true if searching for left-floats, false otherwise

Returns:

The requested float or null if none was found

getAvailableVSpace

public int getAvailableVSpace(int y,
                              int leftX,
                              int rightX)

Returns the available vertical space within the selected bounds

Parameters:

y - Y index to start from

leftX - left bound

rightX - right bound

Returns:

the available height, may be MAX_INT

findLineSpace

public StackManager.LineSpaceInfo findLineSpace(java.awt.Rectangle minRequired,
                                                java.awt.Rectangle bounds,
                                                int clear,
                                                int textAlign)

Tries to find a position, where there is enough room to place the content. This method searches top-down and returns the first possibile position for the content.

Parameters:

minRequired - The minimum of required space to place the content

bounds - Maximum ABSOULTE bounds to place the content. The height will be ignored, it's up to the layout to deal with heights beyond its box. The upper bound has to be the top

clear - The clear attribute of the requesting element

textAlign - The text-align attribute of the requesting element

Returns:

LineSpaceInfo with the required information to place the content

findClearSpace

public StackManager.LineSpaceInfo findClearSpace(java.awt.Rectangle minRequired,
                                                 java.awt.Rectangle bounds,
                                                 int clear,
                                                 int textAlign)

Tries to find a position, where there is enough room to place the content. This method searches top-down and returns the first possibile position for the content.

Parameters:

minRequired - The minimum of required space to place the content

bounds - Maximum ABSOULTE bounds to place the content. The height will be ignored, it's up to the layout to deal with heights beyond its box. The upper bound has to be the top

clear - The clear attribute of the requesting element

textAlign - The text-align attribute of the requesting element

Returns:

LineSpaceInfo with the required information to place the content

notifyNewLine

public void notifyNewLine(float topY)

placed the recently added floats

Parameters:

topY - The highest position possible for the recently added floats

getBottomPosition

public int getBottomPosition(BlockView parent)

The difference between the top of the root-View and the bottom of the lowest float in pixel. Only direct children of the parent will be relevant in this search!

Parameters:

parent - The parent view

Returns:

Number of pixel or 0 if no float has been placed

clear

public void clear()

Removes all known float informations

clearMyFloats

public void clearMyFloats(BoxView parent)

Removes all floats with parent set as their parent.

Parameters:

parent - the parent

hasViews

public boolean hasViews()

Returns the number of floats currently managed by this instance

Returns:

number of floats

getViewForPosition

public ViewPositionInfo getViewForPosition(java.awt.Point position,
                                           java.awt.Rectangle a,
                                           int mode)

Finds the view and it's location for a specific point of the screen

Parameters:

position - the location to search

a - the bounds of THIS view

mode - the part of the views, which have to be painted

Returns:

The bounds and view for the position

See Also:

MODE_NEGATIVE, MODE_FLOATING, MODE_POSITIVE, MODE_ALL_NON_NEGATIVE

getSpan

public java.awt.Rectangle getSpan()

Returns the maximum span in positive direction of the floats handled by this manager

Returns:

the maximum span in positive direction of the floats handled by this manager

notifyBlockFinished

public void notifyBlockFinished(boolean hard)

Notifies the manager, that the containing block, which holds this manager, has finished layouting. This requests the manager to place all recent positioned elements

Parameters:

hard - set to true, if the status of the childviews should be overridden, and all children are requested to update their layout

getSpan

public java.awt.Rectangle getSpan(int mode)

Returns the span of a stack group

Parameters:

mode - the mode constant to address a certain stack group

Returns:

the span of the group, never null

See Also:

MODE_NEGATIVE, MODE_FLOATING, MODE_NEUTRAL, MODE_POSITIVE