draw.controller

Interface IActionInterface

All Known Implementing Classes:

ChangeCursorHandler, CreateHandler, Handler, ResizeHandler, SelectHandler

public interface IActionInterface

This interface describes a number of potential behaviors.

1. Move -- when the user moves the mouse, potentially with key modifiers down but no button pressed.
2. Anchor actions
   1. startAnchor -- press mouse over an anchor for an element
   2. dragAnchor -- drag mouse down to continue action
   3. completeAnchor -- release mouse
3. Empty actions
   1. start -- press mouse over a possible element
   2. drag -- drag mouse down to continue action
   3. complete -- release mouse

Each selected element in the GUI will have four "anchor" squares at the four corners of the bounding box that defines the element. For example:

In handling events, there may be a need to paint directly into the Graphics object being controlled, which is why the paint(Graphics) is provided.

Field Summary

Fields

Modifier and Type	Field and Description
static int	NoAnchor
static int	NorthEastAnchor
static int	NorthWestAnchor
static int	SouthEastAnchor
static int	SouthWestAnchor

Method Summary

Modifier and Type	Method and Description
boolean	complete(java.awt.Point pt, int modifiers, java.util.Optional<Element> element) Complete the mouse interaction.
boolean	completeAnchor(java.awt.Point pt, int modifiers, Element element) Complete the mouse interaction as started by dragType.
boolean	drag(java.awt.Point start, int modifiers, java.util.Optional<Element> element, java.awt.Point current) Act on the mouse drag.
boolean	dragAnchor(java.awt.Point start, int modifiers, Element element, java.awt.Point current) Act on the anchor with mouse down.
boolean	move(java.awt.Point pt, int modifiers, java.util.Optional<Element> element, int anchor) Movement of cursor detected without the mouse button being pressed.
void	paint(java.awt.Graphics g) Provide the capability for any of these controllers to paint into the Graphics object they are controlling.
boolean	start(java.awt.Point pt, int modifiers, java.util.Optional<Element> element) Initiate action by pressing mouse at point with, potentially, a selected element.
boolean	startAnchor(java.awt.Point pt, int modifiers, Element element, int anchor) Start the mouse interaction as started by dragType.

Field Detail

NorthWestAnchor

static final int NorthWestAnchor

See Also:

Constant Field Values

NorthEastAnchor

static final int NorthEastAnchor

See Also:

Constant Field Values

SouthEastAnchor

static final int SouthEastAnchor

See Also:

Constant Field Values

SouthWestAnchor

static final int SouthWestAnchor

See Also:

Constant Field Values

NoAnchor

static final int NoAnchor

See Also:

Constant Field Values

Method Detail

move

boolean move(java.awt.Point pt,
             int modifiers,
             java.util.Optional<Element> element,
             int anchor)

Movement of cursor detected without the mouse button being pressed.

Element is the optional element over which the point is moving. If it is present then there are two options:

1. anchor is one of these values, as it passes over the anchor area.
   • Cursor.NW_RESIZE_CURSOR (6)
   • Cursor.NE_RESIZE_CURSOR (7)
   • Cursor.SE_RESIZE_CURSOR (5)
   • Cursor.SW_RESIZE_CURSOR (4)
2. anchor is zero (0 or NoAnchor) which means it points over an element.

When element is not present, then cursor is moving over some place in which no element intersects.

In all cases, modifiers reflects whether shift or control is down.

Parameters:

pt - mouse location

modifiers - keyboard modifiers in effect

element - optional element in play

anchor - which anchor is affected

Returns:

whether mouse action was processed

start

boolean start(java.awt.Point pt,
              int modifiers,
              java.util.Optional<Element> element)

Initiate action by pressing mouse at point with, potentially, a selected element.

Parameters:

pt - starting an element action at this mouse location

modifiers - keyboard modifiers in effect

element - optional element in play

Returns:

whether mouse action was processed

drag

boolean drag(java.awt.Point start,
             int modifiers,
             java.util.Optional<Element> element,
             java.awt.Point current)

Act on the mouse drag. Pass along modifiers (SHIFT, CONTROL, etc...).

Parameters:

start - original starting mouse location of this drag action

modifiers - keyboard modifiers in effect

element - optional element in play

current - current mouse location

Returns:

whether mouse action was processed

complete

boolean complete(java.awt.Point pt,
                 int modifiers,
                 java.util.Optional<Element> element)

Complete the mouse interaction.

Parameters:

pt - ending mouse location of this mouse action

modifiers - keyboard modifiers in effect

element - optional element in play

Returns:

whether mouse action was processed

startAnchor

boolean startAnchor(java.awt.Point pt,
                    int modifiers,
                    Element element,
                    int anchor)

Start the mouse interaction as started by dragType.

Parameters:

pt - start an anchor at this mouse location

modifiers - keyboard modifiers in effect

element - affected element

anchor - initiating anchor index position

Returns:

whether mouse action was processed

dragAnchor

boolean dragAnchor(java.awt.Point start,
                   int modifiers,
                   Element element,
                   java.awt.Point current)

Act on the anchor with mouse down. Pass along modifiers (SHIFT, CONTROL, etc...)

Parameters:

start - mouse location where action started

modifiers - keyboard modifiers in effect

element - affected element

current - current mouse location

Returns:

whether mouse action was processed

completeAnchor

boolean completeAnchor(java.awt.Point pt,
                       int modifiers,
                       Element element)

Complete the mouse interaction as started by dragType.

Parameters:

pt - ending an anchor action at this mouse location

modifiers - keyboard modifiers in effect

element - affected element

Returns:

whether mouse action was processed

paint

void paint(java.awt.Graphics g)

Provide the capability for any of these controllers to paint into the Graphics object they are controlling.

Parameters:

g - Graphics object being controlled.