developing beyond the component libraries...developing beyond the component libraries users should...

Developing Beyond the Component Libraries

Ryan Cuprakwww.cuprak.net

JavaOne 2010

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Speaker

JavaOne 2010

www.enginuityplm.com

www.ctjava.org

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What makes an application unique?

What it does.

How useful it is.

How a user interacts with it.

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Agenda❖ Why write a custom component?❖ Implementing a custom component❖ Introduction to Java’s L&F❖ Extending Swing components❖ Creating novel components❖ Understanding editor integration❖ Mashing Swing and JavaFX

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Developing Beyond the Component Libraries

❖ Users should not know they are using a Java application.❖ Users approach the computer as a tool for accomplishing a

task. ❖ Users should not be impeded by a user interface.❖ Users should never hear:

“You are limited to a JTextField because Java/Oracle doesn’t provide an ‘X’ GUI widget”

Java’s GUI component architecture is build for extension!

Couple of things before we get started:

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❖ Button❖ Check Box❖ Color Chooser❖ Combo Box❖ Desktop Pane❖ Dialog❖ Editor Pane❖ File Chooser❖ Formatted Field❖ Frame❖ Internal Frame❖ Label

❖ Layered Pane❖ List❖ Menus❖ Option Pane❖ Panel❖ Password Field❖ Progress Bar❖ Radio Button❖ Scroll Bar❖ Scroll Pane❖ Separator❖ Slider

❖ Spinner❖ Split Pane❖ Tabbed Pane❖ Table❖ Text Area❖ Text Field❖ Text Pane❖ Toggle Button❖ Tool Bar❖ Tree

Hasn’t expanded since Swing was introduced.

Why write a custom component?

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❖ Swing component library is a starting point.❖ Applications need more than basic components:

❖ Currency Fields - support multiple currencies❖ Percent Fields - covert to PPM/PPB❖ Date Viewers - render dates❖ Numeric controls - scientific notation, locale aware❖ Text editor - highlight spelling errors

❖ Reduce redundant coding❖ Distinctive appearance

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❖ Decorating components:

❖ Fields containing validation errors

❖ Fields that are required

❖ Auto-focusing on fields with validation errors

❖ Binding and sorting data

❖ Restricting or facilitating data input

❖ Adding new platform controls (Office Ribbon)

❖ Leveraging platform controls (WebKit)


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❖ Does it exist already?❖ Does the functionality really need a new component?❖ Will the component be used in an editor such as NetBeans,

IDEA, Eclipse, JFormDesigner?❖ Is the component locale sensitive?❖ Is the component Look & Feel sensitive?❖ Does it need to support accessibility?

Why write a custom component?Before rushing off to implement components:

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❖ Swingx (swingx.dev.java.net)❖ Flamingo (flamingo.dev.java.net)❖ JIDE Software (www.jidesoft.com/)❖ ILOG (www.ilog.com)❖ Beans Binding (beansbinding.dev.java.net)❖ JGraph (www.jgraph.com)❖ ArcGIS (www.esri.com)❖ JFreeChart (www.jfree.org/jfreechart)❖ JavaFX - controls/effects (http://javafx.com)❖ TWaver - http://www.servasoftware.com

Many More!Don’t reinvent the wheel!


Alternatives to writing a component:

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Which path to take?

❖ Java Swing

❖ Java AWT

❖ JavaFX

❖ SWT

❖ LWUIT

❖ Apache Pivot


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Agenda

❖ Why write a custom component?❖ Implementing a custom component❖ Introduction to Java’s L&F❖ Extending components❖ Creating novel components❖ Understanding editor integration❖ Mashing Swing and JavaFX

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❖ Create new button with a custom appearance:❖ Custom background and border❖ Dashed border around text focused❖ Underline text on roll-over❖ Use the cambria font❖ Text grows with the component

❖ Implementation:1. Subclass javax.swing.JComponent2. Override JComponent.paintComponent(),

getPreferredSize(), getMinimumSize()3. Add a FocusListener4. Add a MouseMotionListener

Implementing a custom component

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Code Demo

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Approach shortcomings:

❖ Reinvents logic already in JButton.

❖ Ignores Look And Feel framework entirely.

❖ Can’t be used as a default button for a dialog.

❖ Doesn’t support HTML labels, icons, etc.

❖ Cannot be extended easily.


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Agenda


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Introduction to Java’s L&FWhat is a LookAndFeel?

❖ LookAndFeel is a set of ComponentUI classes that provide a common theme or appearance for controls.❖ Either cross platform or platform specific.

❖ Transparent to the application programmer using controls (mostly). ❖ LookAndFeels controls:

❖ Key bindings❖ Icons❖ Focus border❖ Text (Locale sensitive)❖ Consistent appearance

❖ Note: UI is skinned in JavaFX with CSS.

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Introduction to Java’s L&FLookAndFeel Hierarchy

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Introduction to Java’s L&F

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Default Look & Feel

❖ MacOS X:

❖ com.apple.laf.AquaLookAndFeel

❖ Windows:

❖ javax.swing.plaf.metal.MetalLookAndFeel


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What are the pieces of a component in Swing?

❖Keystroke handling❖Tooltips❖Accessibility❖Client Properties

❖Painting❖Layout❖Dimensions

JComponent ComponentUI

LookAndFeel Specific

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Introduction to Java’s L&FJComponent

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Introduction to Java’s L&FComponentUI

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Introduction to Java’s L&FComponentUI Instantiation

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So how do we go from a ButtonUI to a MetalButtonUI or an AquaButtonUI?

JButton returns “ButtonUI”, UIDefaults it maps to a MetalButtonUI.

ComponentUI Instantiation

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To sum up the creation process:1. LookAndFeel initializes and populates UIDefaults with a mapping of

UI Class Identifiers to the LookAndFeels implementations.2. JComponent subclass requests its UI delegate from the UIManager (singleton).

3. UI Manager queries the JComponent subclass for its UI Class ID.❖ ButtonUI for JButton❖ TextFieldUI for JTextField

4. UIManager looks up the UIComponent using the UI Class ID:❖ ButtonUI maps to MetalButtonUI

5. UIManager invokes static method createUI(JComponent) on the ComponentUI❖ UI delegate can be a singleton or unique for each component.


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Introduction to Java’s L&FSetting Bounds

Assumes a LayoutManager.JavaOne 2010

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Introduction to Java’s L&FPainting

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❖ Fonts❖ Insets❖ Shadows❖ Icons❖ Borders❖ Foreground color❖ Background color

❖ Input Maps❖ Margins❖ Mnemonic❖ Opaque flag❖ Caret blink rate❖ Disabled colors❖ etc.


UIDefaults stores settings used to by the components:

Defaults

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Introduction to Java’s L&FDefaults

InstallUI method on ComponentUI loads default values.

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❖ Many changes to Swing components cannot be made by simply overriding a component’s paint() method.

❖ Major changes to a component must be made in the ComponentUI:❖ Joining of cells in JTable❖ Custom popup for adding/removing table columns❖ Changing the disabled color of the text on a

JRadioButton❖ Radically changing or altering the appearance of a

component.


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Introduction to Java’s L&F3 Steps to Component Creation

Subclass JComponent

Subclass ComponentUI

Register with UIManagerThis sounds simple right?

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Agenda


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Customize three existing components:

❖ JButton - create an ObsidianButton

❖ JTextField - Currency Editor

❖ JRootPane - customize window border/buttons.

Extending ComponentsObjectives

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❖ Objective implement the Obsidian Button correctly.

❖ ObsidianButton recipe:

❖ Extend ButtonUI - ObsidianButtonUI

❖ Extend JButton - ObsidianButton

❖ Register with UIManager

Extending ComponentsObsidian Button

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Tidbits:

❖ ButtonModel contains the current state of the button.

❖ BasicButtonUI has hooks to ease extensions.

Extending ComponentsObsidian Button

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Extending Components

Code Demo

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❖ Why create a currency control?❖ Restrict user input to just numeric data.❖ Control the presentation of the currency.❖ Control the interpretation of the number.❖ Control the input of the number.

❖ Why not use JFormattedTextField?❖ How is invalid user input interpreted?❖ Controlling locale/currency settings independently.

Extending ComponentsCurrency Control

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JFormattedTextField Demo

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How is a text field rendered?

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Recipe for implementing the currency control:

1. Create a FieldView subclass to do the custom rendering.

2. Create a new BasicTextFieldUI subclass.

1. Override the create method and return the new FieldView

3. Create a new JTextField subclass

1. Return the new BasicTextFieldUI subclass


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Code Demo

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Currency Control

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Food for thought:

You can radically change the rendering of a document.

Consider for example restricting input to ABCDEFG and creating a view that renders it like:

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What’s the matter with the standard JRootPane?

Extending ComponentsJRootPane

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Because sometimes you want to customize it!

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Recipe for customizing the title pane:

1.Create a JComponent subclass to render the title pane.

2.Extend RootPaneUI

3.Extend your Look And Feel:

1. In initClassDefaults perform the following configuration:JDialog.setDefaultLookAndFeelDecorated(true);JFrame.setDefaultLookAndFeelDecorated(true);

2.Return true for getSupportsWindowDecorations()

Extending ComponentsJRootPane

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Code Demo

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JRootPane

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Agenda

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❖ Components to be demoed:❖ iPhone Switch Component

❖ What we will see:❖ Supporting multiple Look & Feels❖ Handling focus and keyboard events

Creating Novel Components

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Creating Novel ComponentsLet’s look at replicating the iPhone switch. ❖ Simple “Toggle” button that slides

back and forth for On and Off.❖ Tapping on the opposite state causes

the button to toggle with a visible animation.

❖ Dragging the switch with the mouse moves the button.

❖ Releasing the button causes the button to snap the nearest side.

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❖ Gradient Paints

❖ Rounded Borders

❖ Not 50/50

❖ Highlights

❖ Border effects

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Creating Novel Components1. JComponent Approach

1. Subclass JComponent.2. Override

paintComponent()2. LookAndFeel Approach

1. Subclass JToggleButton2. Create a ComponentUI

subclass.

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❖ Implement listeners for:FocusLister, MouseListener, MotionListener, KeyboardListener

❖ Track and render states:Focus, Enabled/Disabled

❖ Support Accessibility❖ Match L&F Appearance/Theme❖ Paint the control (and have it look professional)

Creating Novel ComponentsJComponent Approach Challenges

This is not trivial!

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❖ Matching current L&F is not trivial:❖ Borders❖ Shadowing❖ Font❖ Background/Foreground Colors❖ Painting (gradients)❖ Keybindings

❖ Matching multiple L&F is even more challenging.❖ Users change themes (Windows Appearance settings).

Creating Novel ComponentsJComponent Approach Challenges

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Code Demo


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Agenda

❖ Why write a custom component?❖ Implementing a custom component❖ Introduction to Java’s L&F❖ Changing Swing’s appearance❖ Creating novel components❖ Understanding editor integration❖ Mashing Swing and JavaFX

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Understanding Editor Integration

Why editor integrations?❖ Manually writing swing code is time consuming.❖ Many good editors for constructing Swing interfaces.❖ Have you ever tried maintaining code like this?

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❖ Supporting editors such as NetBeans:

❖ Create BeanInfo objects for each component.

❖ Each component property should support PropertyChangeEvents (Beans Bindings).

❖ Include an icon representing the component.

❖ Support serialization.

Understanding Editor Integration

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Understanding Editor IntegrationAdding SwingX widgets to NetBeans.

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Agenda

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❖ Why JavaFX vs. Swing?❖ Scene graph❖ Integration with Photoshop/Illustrator❖ Skin controls with CSS❖ Rich media support❖ JavaFX 1.3 added lots of controls.

❖ Why Swing vs JavaFX?❖ Rich component libraries❖ Support native Look And Feels

❖ Why mix JavaFX and Swing?❖ Get the best of both worlds!

Mashing Swing and JavaFX

These are just a few reasons!

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Mashing Swing and JavaFX

Code Demo

Using JavaFX with Swing

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❖ How to start writing components:❖ Browse the source to Java Swing library (src.jar).❖ Excellent open source projects (read/debug):

❖ SwingX (https://swingx.dev.java.net/)❖ JIID Software Open Layer (http://www.jidesoft.com/)

❖ Tools:❖ Java Decompiler (http://java.decompiler.free.fr/)

❖ Links:❖ http://www.l2fprod.com (Look & Fool)❖ http://today.java.net/article/2007/02/19/how-write-

custom-swing-component

Starting Points

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Reference MaterialFurther Reading:

❖ Core Swing Advanced Programming by Kim Topley (0130832928)

❖ Filthy Rich Clients by Chet Hasse/Romain Guy (0-13-241393-0)

❖ JavaFX in Action by Simon Morris (1-933988-99-1)

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Recap component development:

❖ ComponentUI - renders a component.

❖ JComponent - delegates rendering to its ComponentUI.

❖ ComponentUIs are looked up via the UIManager.

❖ Components can be customized via UIDefaults

Summary

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❖ Don’t reinvent the wheel!

❖ Test on multiple platforms.

❖ Write a test harness to verify:

❖ Changing Locale

❖ Changing Look and Feel

❖ Enabling/disabling programmatically

Summary

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Q&ACode samples/slides: www.cuprak.netQuestions: [email protected]

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developing beyond the component libraries...developing beyond the component libraries users should...

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