ewe.ui
Class Canvas

java.lang.Object
  ewe.ui.ControlBase
      ewe.ui.Control
          ewe.ui.Container
              ewe.ui.Canvas

All Implemented Interfaces:

CellConstants, ControlConstants, EventListener, ImageRefresher, IScroll, ScrollClient, TimerProc, UIConstants

Direct Known Subclasses:

ImageControl, Mosaic, PageDisplay, Panel, ScrollableHolder, TransparentPicker

public class Canvas

extends Container

implements ScrollClient

A Canvas is a general Control that is the best control to extend if you are designing a control that may be used as Container or that may need to be scrolled.

Field Summary

protected boolean	isFullScrollClient Overriding classes must set this true if the new class fully implements the ScrollClient interface (which Canvas does not).
Point	origin This is the origin for the Canvas.
int	scrollPercent
Rect	virtualSize

Fields inherited from class ewe.ui.Container

closedFocus, cycleFocus, dontAutoScroll, dontFocusOnChildren

Fields inherited from class ewe.ui.Control

_debug, backGround, beforeRemoved, borderColor, borderStyle, borderWidth, children, columns, constraints, DoPaintMethod, dragging, dragResolution, dragTime, exitKeys, fieldTransfer, font, foreGround, haveNativePaint, height, holdDownPause, holdTick, hotKey, image, lastSelected, listeners, maxHeight, maxWidth, menuState, minHeight, minWidth, modifiers, MyClass, name, next, np, parent, penStatus, popupSound, popupSoundClip, preferredHeight, preferredWidth, prev, prompt, promptControl, rows, ss, standardBorder, standardEdge, startDragResolution, tags, tail, text, toolTip, width, x, y

Fields inherited from class ewe.ui.ControlBase

clipItems, clipObject, clipOwner, curPoint, currentPenEvent, debugControl, debugFlag, DidHoldDown, doubleBuffer, doubleClickTime, firstPress, globalDrawFlat, globalEditable, globalEnabled, globalPalmStyle, globalSmallControls, GotPenDown, PenIsOn, pressPoint, TAG_LAST_USER_DATA, TAG_USER_DATA, TAKE_FIRST_PRESS, unnamed, useNativeTextInput

Fields inherited from interface ewe.ui.IScroll

Higher, Horizontal, Lower, OPTION_INDICATOR_ONLY, PageHigher, PageLower, ScrollHigher, ScrollLower, TrackTo, Vertical

Fields inherited from interface ewe.ui.UIConstants

BDR_DOTTED, BDR_INNER, BDR_NOBORDER, BDR_OUTER, BDR_OUTLINE, BDR_RAISEDINNER, BDR_RAISEDOUTER, BDR_SUNKENINNER, BDR_SUNKENOUTER, BF_BOTTOM, BF_BOTTOMLEFT, BF_BOTTOMRIGHT, BF_BUTTON, BF_DIAGONAL, BF_DIAGONAL_ENDBOTTOMLEFT, BF_DIAGONAL_ENDBOTTOMRIGHT, BF_DIAGONAL_ENDTOPLEFT, BF_DIAGONAL_ENDTOPRIGHT, BF_EXACT, BF_FLAT, BF_LEFT, BF_MIDDLE, BF_MONO, BF_PALM, BF_RECT, BF_RIGHT, BF_SOFT, BF_SQUARE, BF_TOP, BF_TOPLEFT, BF_TOPRIGHT, EDGE_BUMP, EDGE_ETCHED, EDGE_RAISED, EDGE_SUNKEN

Fields inherited from interface ewe.ui.CellConstants

BORDER, BOTTOM, CELLFLAG, CELLMASK, CENTER, CONTROLMASK, DONTCHANGE, DONTFILL, DONTSTRETCH, EAST, FILL, FIXEDSIZE, GROW, HCENTER, HCONTRACT, HEXPAND, HFILL, HGROW, HSHRINK, HSTRETCH, INITIALLY_CLOSED, INITIALLY_MINIMIZED, INITIALLY_PREFERRED_SIZE, INSETS, LEFT, MAXIMUMSIZE, MINIMUMSIZE, NORTH, NORTHEAST, NORTHWEST, PREFERREDSIZE, RECT, RIGHT, SHRINK, SOUTH, SOUTHEAST, SOUTHWEST, SPAN, STRETCH, TEXTSIZE, TOP, VCENTER, VCONTRACT, VEXPAND, VFILL, VGROW, VSHRINK, VSTRETCH, WEST

Fields inherited from interface ewe.ui.ControlConstants

All, AlwaysEnabled, AlwaysRecalculateSizes, ByDeferredMouse, ByDeferredPen, ByFrameChange, ByKeyboard, ByMouse, ByPen, ByRequest, CalculatedSizes, Disabled, DisablePopupMenu, DisplayOnly, Down, DrawFlat, Flag, ForceResize, HasData, Invisible, KeepImage, KeepSIP, Left, MakeMenuAtLeastAsWide, Maximize, Minimize, MouseSensitive, NoFocus, NotAnEditor, NotEditable, PaintDataOnly, PaintOutsideOnly, PenTransparent, PreferredSizeOnly, Right, SendUpKeyEvents, SendUpPenEvents, ShowSIP, ShrinkToNothing, SmallControl, SpecialBackground, TakeControlEvents, TakesKeyFocus, Transparent, Up, WantDrag, WantHoldDown

Fields inherited from interface ewe.fx.ImageRefresher

KEEP_VISIBLE

Constructor Summary

Canvas()

Method Summary

boolean	canGo(int orientation, int direction, int position)
boolean	canScreenScroll() This should return true if pixel scrolling of the on-screen data is allowed.
void	checkScrolls()
void	doBorder(Graphics g)
void	doScroll(int which, int action, int value)
void	fixOrigin()
int	getActual(int which)
Image	getBuffer()
int	getCurrent(int which)
Dimension	getDisplayedSize(Dimension dest)
Dimension	getMySize(Dimension dest)
protected int	getPercent(int size, int percent, int minimum)
ScrollablePanel	getScrollablePanel() Return a ScrollablePanel (usually a ScrollBarPanel) which contains this Control.
ScrollClient	getScrollClient() Return a fully implemented ScrollClient for this Control.
int	getVisible(int which, int forSize)
Rect	getVisibleArea(Rect dest)
boolean	needScrollBar(int which, int forSize)
void	onScroll(int movedX, int movedY)
void	onSetOrigin()
void	reduceClip(Graphics g, Rect r)
boolean	scroll(int dx, int dy) Scroll the panel - this does not update the ScrollBars.
boolean	scroll(int dx, int dy, Point moved) Scroll the panel and save in moved, the amount of distance moved in x and y.
boolean	scrollToVisible(int x, int y, int width, int height)
boolean	setOrigin(int nx, int ny, Point moved)
void	updateScrollServer(int which)

Methods inherited from class ewe.ui.Container

_paintChildren, add, addDirectly, containerHasFocus, dismantle, dismantle, doHotKey, findChild, focusFirst, focusFirst, focusOnContainer, focusOnData, getChildren, getChildrenBackwards, getFirstFocus, getNextKeyFocus, gotFocus, lostFocus, remove, removeAll, repaintDataNow, takeFocus, takePromptControl

Methods inherited from class ewe.ui.Control

acceptsData, activate, addListener, addTimer, amOnTopFrame, calculateSizes, calculateTextSize, cancelCut, cancelHoldDown, canEdit, chainDataChange, change, checkClipboardOperations, checkExitKey, checkMenu, checkMenuKey, checkModifiers, checkPenTransparent, clearTag, clipboardToString, clipboardTransfer, closeMenu, contains, contains, createGraphics, dataAccepted, dataBeingRemoved, dataDraggedOff, dataDraggedOver, dataDraggedOver, dataDroppedOn, dataTransferCancelled, deactivate, defaultTo, doAction, doActionKey, doBackground, doMenu, dontAcceptDrop, doPaint, doPaintChildren, doPaintChildren, doPaintChildren, doPaintData, doPaintData, doShowMenu, dragged, exitEntry, fillBackground, formClosing, fromClipboard, fromField, fromField, getAllDescendants, getAllSubControls, getBackground, getClipboardMenu, getClipObject, getControlBuffer, getControlBuffer, getDataRect, getDataToCopy, getDataToDragAndDrop, getDim, getDisplayText, getDragAndDropContext, getFont, getFontMetrics, getFontMetrics, getForeground, getFrame, getFrameOrContainer, getGraphics, getImage, getLastSelected, getLocation, getMaximumSize, getMenu, getMinimumSize, getModifiers, getNext, getParent, getPasswordCharacter, getPosInFrame, getPosInParent, getPreferredSize, getPrompt, getPromptText, getRect, getRect, getServer, getSize, getSizes, getSubControls, getTag, getText, getToolTip, getWindow, hasModifier, hasPopupFormAttached, hasTag, inheritModifiers, isChildOf, isModal, isOnMe, isSomeonesHotKey, make, makeFrameTopMost, makeHot, menuIsActive, modify, modifyAll, modifyAll, notifyAction, notifyDataChange, notifyDataChange, notNative_doPaintChildren, oldButWorksDoPaintChildren, oldPaintChildren, oldPostEvent, onControlEvent, onEvent, onKeyEvent, onLabelPenEvent, onPaint, onPenEvent, paintBackground, paintChildren, penClicked, penDoubleClicked, penHeld, penPressed, penReleased, penRightReleased, popupBeep, popupMenuClosed, popupMenuEvent, popupMenuEvent, postEvent, recalculatePreferredSize, redisplay, refresh, removeListener, removeTimer, repaint, repaintNow, repaintNow, repaintNow, requestPaint, requestResizeTo, resetRect, resizeTo, restore, scrollAndRepaint, sendToListeners, set, setBorder, setCell, setClipObject, setControl, setCursor, setFixedSize, setFont, setHotKey, setHotKey, setLocation, setMaximumSize, setMenu, setMinimumSize, setPreferredSize, setPromptControl, setRect, setRect, setServer, setTag, setTags, setText, setTextSize, setToolTip, show, shown, standardOnKeyEvent, startDragAndDrop, startDragAndDrop, startDragging, stopDragging, takeData, takeFromClipboard, testDim, ticked, toClipboard, toField, toField, toString, toTextData, transferPenPress, transferPenPress, tryDragAndDrop, tryNext, tryStartMenu, updateData, willAcceptDrop, willShowFrame

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode

Methods inherited from interface ewe.ui.ScrollClient

getServer, setServer

Field Detail

virtualSize

public Rect virtualSize

origin

public Point origin

This is the origin for the Canvas. If it is null then it should be considered to be (0,0)

scrollPercent

public int scrollPercent

isFullScrollClient

protected boolean isFullScrollClient

Overriding classes must set this true if the new class fully implements the ScrollClient interface (which Canvas does not).

Constructor Detail

Canvas

public Canvas()

Method Detail

getDisplayedSize

public Dimension getDisplayedSize(Dimension dest)

getMySize

public Dimension getMySize(Dimension dest)

getBuffer

public Image getBuffer()

reduceClip

public void reduceClip(Graphics g,
                       Rect r)

getVisibleArea

public Rect getVisibleArea(Rect dest)

fixOrigin

public void fixOrigin()

onScroll

public void onScroll(int movedX,
                     int movedY)

onSetOrigin

public void onSetOrigin()

setOrigin

public boolean setOrigin(int nx,
                         int ny,
                         Point moved)

getVisible

public int getVisible(int which,
                      int forSize)

Specified by:

getVisible in interface ScrollClient

getActual

public int getActual(int which)

Specified by:

getActual in interface ScrollClient

getCurrent

public int getCurrent(int which)

Specified by:

getCurrent in interface ScrollClient

needScrollBar

public boolean needScrollBar(int which,
                             int forSize)

Specified by:

needScrollBar in interface ScrollClient

canGo

public boolean canGo(int orientation,
                     int direction,
                     int position)

Specified by:

canGo in interface ScrollClient

checkScrolls

public void checkScrolls()

updateScrollServer

public void updateScrollServer(int which)

scroll

public boolean scroll(int dx,
                      int dy,
                      Point moved)

Scroll the panel and save in moved, the amount of distance moved in x and y. Scroll the panel - this does not update the ScrollBars. To do so you should call checkScrolls().

Parameters:

dx - The x distance to move.

dy - The y distance to move.

moved - The actual x and y distance moved. This may be different to dx and dy since the the Canvas may limit the location the origin can actually be.

Returns:

true if a scroll was done, false if not.

canScreenScroll

public boolean canScreenScroll()

This should return true if pixel scrolling of the on-screen data is allowed.

scroll

public boolean scroll(int dx,
                      int dy)

Scroll the panel - this does not update the ScrollBars. To do so you should call checkScrolls().

Parameters:

dx - The x distance to move.

dy - The y distance to move.

Returns:

true if a scroll was done, false if not.

getPercent

protected int getPercent(int size,
                         int percent,
                         int minimum)

doScroll

public void doScroll(int which,
                     int action,
                     int value)

Specified by:

doScroll in interface ScrollClient

doBorder

public void doBorder(Graphics g)

Overrides:

doBorder in class Control

getScrollClient

public ScrollClient getScrollClient()

Return a fully implemented ScrollClient for this Control. This will return this Control if it fully implements ScrollClient otherwise it will return a ScrollableHolder containing this Control.

getScrollablePanel

public ScrollablePanel getScrollablePanel()

Return a ScrollablePanel (usually a ScrollBarPanel) which contains this Control.

scrollToVisible

public boolean scrollToVisible(int x,
                               int y,
                               int width,
                               int height)

Overrides:

scrollToVisible in class Container