jscicalc.DisplayPanel Class Reference

This class is responsible for the LCD-like display in the calculator. More...

Inheritance diagram for jscicalc.DisplayPanel:

Collaboration diagram for jscicalc.DisplayPanel:

[legend]

List of all members.

Public Member Functions
	DisplayPanel (final ReadOnlyCalculatorApplet applet)
	The constructor takes a ReadOnlyCalculatorApplet so that it has an interface to the CalculatorApplet object.
void	setUp ()
	Set up the panel.
void	paintComponent (java.awt.Graphics graphics)
	This probably does nothing.
void	left ()
	Used by CalculatorApplet in response to a LeftButton Action to ask the EntryLabel to move the caret on place left.
void	right ()
	Used by CalculatorApplet in response to a RightButton Action to ask the EntryLabel to move the caret on place right.
void	update (boolean entry, boolean extra)
	Updates the panel.
javax.swing.Action	backward ()
	This was designed to collect an Action so we could move the Caret from within the CalculatorApplet, but I couldn’t get it to work so used left() instead.
void	setExpression (Parser parser)
	Set the current expression.
void	newExpression ()
	Sets a new expression in EntryLabel.
void	clear (Parser parser)
	Clears the current expression and the Parser.
void	delete (Parser parser)
	Deletes the PObject at the current Caret position.
void	insert (PObject p, Parser parser)
	Inserts a PObject at the current Caret position.
void	setOn (boolean value)
	Set state (on/off).
boolean	getOn ()
	Get state (on/off).
void	setValue ()
	Set the diplayLabel value to match the OObject in the applet.
ReadOnlyCalculatorApplet	getApplet ()
	Get an interface for the CalculatorApplet object.
final DisplayLabel	getDisplayLabel ()
	Udes by CalculatorApplet to get DisplayLabel.
void	setCaretToEntry ()
	Set Caret to entry.
void	setCaretToDisplay ()
	Set Caret to display.
boolean	hasCaret (final ScrollableLabel scrollableLabel)
	Find if scrollableLabel has the Caret.
boolean	displayLabelHasCaret ()
	Find if displayLabel has the Caret.
Package Functions
final boolean	displayLabelScrollable ()
	Find if it is possible to scroll within the display label.
Private Attributes
ScrollableLabel	labelWithCaret
EntryLabel	entryLabel
	The entry label: shows what you’ve typed.
DisplayLabel	displayLabel
	The display label: shows results of calculations.
ExtraPanel	extraPanel
	The panel that shows calculator state: shift, Stat mode, degrees or radians, Base and the like.
MiniPanel	leftPanel
	Panel to show left movement of display is possible.
MiniPanel	rightPanel
	Panel to show right movement of display is possible.
final ReadOnlyCalculatorApplet	applet
	Interface to the CalculatorApplet object that allows us to read values but not to change their state.
boolean	on
	State of calculator on or off.
Static Private Attributes
static final long	serialVersionUID = 1L

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Detailed Description

This class is responsible for the LCD-like display in the calculator.

When a particular CalculatorPanel is made current by CalculatorApplet.setDisplayPanel() through CalculatorPanel.setDisplayPanel() the instance of this class is attached to the the CalculatorPanel. I’m not sure if this is handled entirely correctly yet because the DisplayPanel has actually been added to more than one CalculatorPanel, which I think swing doesn’t permit. However, it works provided we reattach it.

Author:

J. D. Lamb

Version:

Revision

1.8

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Constructor & Destructor Documentation

jscicalc.DisplayPanel.DisplayPanel

(

final ReadOnlyCalculatorApplet

applet

)

The constructor takes a ReadOnlyCalculatorApplet so that it has an interface to the CalculatorApplet object.

It doesn’t need to can modify the CalculatorApplet object and so it doesn’t need access to all members. Forby, despite its general moralistic tendencies, Java doesn’t let you specify that an object is const.

Parameters:

applet

The CalculatorApplet object (accessed through a read-only interface)

References jscicalc.DisplayPanel.displayLabel, jscicalc.DisplayPanel.entryLabel, jscicalc.DisplayPanel.extraPanel, jscicalc.DisplayPanel.leftPanel, jscicalc.DisplayPanel.rightPanel, and jscicalc.DisplayPanel.setCaretToEntry().

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Member Function Documentation

void jscicalc.DisplayPanel.setUp

(

)

Set up the panel.

Everything is kept in place by a SpringLayout.

See also:

CalculatorApplet.getFrameWidth()

CalculatorApplet.getFrameHeight()

References jscicalc.ReadOnlyCalculatorApplet.buttonWidth(), jscicalc.ReadOnlyCalculatorApplet.displayHeight(), jscicalc.DisplayPanel.displayLabel, jscicalc.DisplayPanel.entryLabel, jscicalc.DisplayPanel.extraPanel, jscicalc.ReadOnlyCalculatorApplet.extraTextSize(), jscicalc.DisplayPanel.getApplet(), jscicalc.DisplayPanel.leftPanel, jscicalc.ReadOnlyCalculatorApplet.minSize(), jscicalc.DisplayPanel.rightPanel, and jscicalc.ReadOnlyCalculatorApplet.strutSize().

Referenced by jscicalc.CalculatorApplet.setPanels().

void jscicalc.DisplayPanel.paintComponent

(

java.awt.Graphics

graphics

)

This probably does nothing.

I’m not quite sure I've got this right. I'm trying to make sure the background is always white: probably even that should be replaced by a specified colour stored in CalculatorApplet.

Parameters:

graphics

The graphics context required.

void jscicalc.DisplayPanel.left

(

)

Used by CalculatorApplet in response to a LeftButton Action to ask the EntryLabel to move the caret on place left.

It’s important CalculatorApplet controls this as it’s the only thing that can read the Parser and so know whether the caret can move left.

References jscicalc.DisplayPanel.labelWithCaret, and jscicalc.ScrollableLabel.left().

Referenced by jscicalc.CalculatorApplet.left().

void jscicalc.DisplayPanel.right

(

)

Used by CalculatorApplet in response to a RightButton Action to ask the EntryLabel to move the caret on place right.

It’s important CalculatorApplet controls this as it’s the only thing that can read the Parser and so know whether the caret can move right.

References jscicalc.DisplayPanel.labelWithCaret, and jscicalc.ScrollableLabel.right().

Referenced by jscicalc.CalculatorApplet.right().

void jscicalc.DisplayPanel.update	(	boolean	entry,
		boolean	extra
	)

Updates the panel.

The second parameter is not used but in principle could let us update only the EntryPanel and not the ExtraPanel. We sometimes don’t want to update the EntryPanel immediately. For example, when we evaluate an expression, we clear the expression in the parser but wait until we start typing a new expression before updating the EntryPanel.

Parameters:

	entry	Should we update EntryPanel?
	extra	Should we update ExtraPanel? (ignored anyway)

References jscicalc.BOTH, jscicalc.DisplayPanel.displayLabel, jscicalc.DisplayPanel.displayLabelHasCaret(), jscicalc.DisplayPanel.entryLabel, jscicalc.DisplayPanel.extraPanel, jscicalc.DisplayLabel.getScrollDirections(), jscicalc.LEFT, jscicalc.DisplayPanel.leftPanel, jscicalc.NEITHER, jscicalc.DisplayPanel.on, jscicalc.RIGHT, jscicalc.DisplayPanel.rightPanel, jscicalc.MiniPanel.setIlluminated(), jscicalc.DisplayLabel.update(), and jscicalc.EntryLabel.update().

Referenced by jscicalc.CalculatorApplet.updateDisplay().

final boolean jscicalc.DisplayPanel.displayLabelScrollable

(

)

[package]

Find if it is possible to scroll within the display label.

Returns:

true or false according as we can or cannot scroll the display label

References jscicalc.DisplayPanel.displayLabel, and jscicalc.DisplayLabel.getScrollDirections().

Referenced by jscicalc.CalculatorApplet.downHistory().

javax.swing.Action jscicalc.DisplayPanel.backward

(

)

This was designed to collect an Action so we could move the Caret from within the CalculatorApplet, but I couldn’t get it to work so used left() instead.

Returns:

An Action: move Caret left

References jscicalc.EntryLabel.backward(), and jscicalc.DisplayPanel.entryLabel.

Referenced by jscicalc.CalculatorApplet.backward().

void jscicalc.DisplayPanel.setExpression

(

Parser

parser

)

Set the current expression.

We pass a Parser because this class shouldn’t access the Parser object directly.

Parameters:

parser

The Parser, which contains the expression

References jscicalc.DisplayPanel.entryLabel, and jscicalc.EntryLabel.setExpression().

Referenced by jscicalc.CalculatorApplet.clear(), jscicalc.CalculatorApplet.downHistory(), and jscicalc.CalculatorApplet.upHistory().

void jscicalc.DisplayPanel.newExpression

(

)

Sets a new expression in EntryLabel.

This doesn’t immediately clear the old expression but does disable Caret movements.

References jscicalc.DisplayPanel.entryLabel, and jscicalc.ScrollableLabel.newExpression.

Referenced by jscicalc.CalculatorApplet.newExpression().

void jscicalc.DisplayPanel.clear

(

Parser

parser

)

Clears the current expression and the Parser.

Probably it should only clear the expression because CalculatorApplet should be the only object changing the state of the parser.

Parameters:

parser

The Parser, which contains the expression

References jscicalc.EntryLabel.clear(), and jscicalc.DisplayPanel.entryLabel.

Referenced by jscicalc.CalculatorApplet.clear().

void jscicalc.DisplayPanel.delete

(

Parser

parser

)

Deletes the PObject at the current Caret position.

Probably it should only change the expression because CalculatorApplet should be the only object changing the state of the parser.

Parameters:

parser

The Parser, which contains the expression

References jscicalc.EntryLabel.delete(), and jscicalc.DisplayPanel.entryLabel.

Referenced by jscicalc.CalculatorApplet.delete().

void jscicalc.DisplayPanel.insert	(	PObject	p,
		Parser	parser
	)

Inserts a PObject at the current Caret position.

Probably it should only change the expression because CalculatorApplet should be the only object changing the state of the parser.

Parameters:

	p	The PObject: typically generated by a CalculatorButton
	parser	The Parser, which contains the expression

References jscicalc.DisplayPanel.entryLabel, and jscicalc.EntryLabel.insert().

Referenced by jscicalc.CalculatorApplet.insert().

void jscicalc.DisplayPanel.setOn

(

boolean

value

)

Set state (on/off).

Probably should always get this state from CalculatorApplet because the states should match.

Parameters:

value

true for on, false for off.

References jscicalc.DisplayPanel.on.

Referenced by jscicalc.CalculatorApplet.setOn().

boolean jscicalc.DisplayPanel.getOn

(

)

Get state (on/off).

Probably should always get this state from CalculatorApplet because the states should match.

Returns:

true for on, false for off.

Implements jscicalc.ReadOnlyDisplayPanel.

References jscicalc.DisplayPanel.on.

Referenced by jscicalc.CalculatorApplet.getOn().

void jscicalc.DisplayPanel.setValue

(

)

Set the diplayLabel value to match the OObject in the applet.

References jscicalc.DisplayPanel.displayLabel, and jscicalc.DisplayLabel.setNewExpression().

Referenced by jscicalc.CalculatorApplet.setValue().

ReadOnlyCalculatorApplet jscicalc.DisplayPanel.getApplet

(

)

Get an interface for the CalculatorApplet object.

Returns:

an interface for the CalculatorApplet object.

Implements jscicalc.ReadOnlyDisplayPanel.

References jscicalc.DisplayPanel.applet.

Referenced by jscicalc.DisplayPanel.setUp().

final DisplayLabel jscicalc.DisplayPanel.getDisplayLabel

(

)

Udes by CalculatorApplet to get DisplayLabel.

References jscicalc.DisplayPanel.displayLabel.

void jscicalc.DisplayPanel.setCaretToEntry

(

)

Set Caret to entry.

References jscicalc.DisplayPanel.displayLabel, jscicalc.DisplayPanel.entryLabel, jscicalc.DisplayPanel.labelWithCaret, and jscicalc.ScrollableLabel.updateCaretVisibility().

Referenced by jscicalc.DisplayPanel.DisplayPanel(), and jscicalc.CalculatorApplet.setCaretToEntry().

void jscicalc.DisplayPanel.setCaretToDisplay

(

)

Set Caret to display.

References jscicalc.DisplayPanel.displayLabel, jscicalc.DisplayPanel.entryLabel, jscicalc.DisplayPanel.labelWithCaret, and jscicalc.ScrollableLabel.updateCaretVisibility().

Referenced by jscicalc.CalculatorApplet.setCaretToDisplay().

boolean jscicalc.DisplayPanel.hasCaret

(

final ScrollableLabel

scrollableLabel

)

Find if scrollableLabel has the Caret.

This allows us to query the interface and find whether EntryPanel or DisplayPanel has permission to display a Caret

Parameters:

scrollableLabel

The Scrollable label we wish to know about

Returns:

true or false according as scrollableLabel has or has not permission to show a Caret

Implements jscicalc.ReadOnlyDisplayPanel.

References jscicalc.DisplayPanel.labelWithCaret.

Referenced by jscicalc.DisplayPanel.displayLabelHasCaret().

boolean jscicalc.DisplayPanel.displayLabelHasCaret

(

)

Find if displayLabel has the Caret.

This allows us to query the interface and find whether EntryPanel or DisplayPanel has permission to display a Caret

Returns:

true or false according as displayLabel has or has not permission to show a Caret

References jscicalc.DisplayPanel.displayLabel, and jscicalc.DisplayPanel.hasCaret().

Referenced by jscicalc.DisplayPanel.update(), and jscicalc.CalculatorApplet.upHistory().

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Member Data Documentation

ScrollableLabel jscicalc.DisplayPanel.labelWithCaret [private]

Referenced by jscicalc.DisplayPanel.hasCaret(), jscicalc.DisplayPanel.left(), jscicalc.DisplayPanel.right(), jscicalc.DisplayPanel.setCaretToDisplay(), and jscicalc.DisplayPanel.setCaretToEntry().

EntryLabel jscicalc.DisplayPanel.entryLabel [private]

The entry label: shows what you’ve typed.

Referenced by jscicalc.DisplayPanel.backward(), jscicalc.DisplayPanel.clear(), jscicalc.DisplayPanel.delete(), jscicalc.DisplayPanel.DisplayPanel(), jscicalc.DisplayPanel.insert(), jscicalc.DisplayPanel.newExpression(), jscicalc.DisplayPanel.setCaretToDisplay(), jscicalc.DisplayPanel.setCaretToEntry(), jscicalc.DisplayPanel.setExpression(), jscicalc.DisplayPanel.setUp(), and jscicalc.DisplayPanel.update().

DisplayLabel jscicalc.DisplayPanel.displayLabel [private]

The display label: shows results of calculations.

Referenced by jscicalc.DisplayPanel.displayLabelHasCaret(), jscicalc.DisplayPanel.displayLabelScrollable(), jscicalc.DisplayPanel.DisplayPanel(), jscicalc.DisplayPanel.getDisplayLabel(), jscicalc.DisplayPanel.setCaretToDisplay(), jscicalc.DisplayPanel.setCaretToEntry(), jscicalc.DisplayPanel.setUp(), jscicalc.DisplayPanel.setValue(), and jscicalc.DisplayPanel.update().

ExtraPanel jscicalc.DisplayPanel.extraPanel [private]

The panel that shows calculator state: shift, Stat mode, degrees or radians, Base and the like.

Referenced by jscicalc.DisplayPanel.DisplayPanel(), jscicalc.DisplayPanel.setUp(), and jscicalc.DisplayPanel.update().

MiniPanel jscicalc.DisplayPanel.leftPanel [private]

Panel to show left movement of display is possible.

Referenced by jscicalc.DisplayPanel.DisplayPanel(), jscicalc.DisplayPanel.setUp(), and jscicalc.DisplayPanel.update().

MiniPanel jscicalc.DisplayPanel.rightPanel [private]

Panel to show right movement of display is possible.

Referenced by jscicalc.DisplayPanel.DisplayPanel(), jscicalc.DisplayPanel.setUp(), and jscicalc.DisplayPanel.update().

final ReadOnlyCalculatorApplet jscicalc.DisplayPanel.applet [private]

Interface to the CalculatorApplet object that allows us to read values but not to change their state.

Referenced by jscicalc.DisplayPanel.getApplet().

boolean jscicalc.DisplayPanel.on [private]

State of calculator on or off.

This should be removed because only the CalculatorApplet should have this information.

Referenced by jscicalc.DisplayPanel.getOn(), jscicalc.DisplayPanel.setOn(), and jscicalc.DisplayPanel.update().

final long jscicalc.DisplayPanel.serialVersionUID = 1L [static, private]

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The documentation for this class was generated from the following file:

• DisplayPanel.java