JavaFX深度指南：打造富客户端应用的Java技术全解 - CSDN文库

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《Pro-Java-FX-2：利用Java技术打造丰富客户端的权威指南》是一本深入探讨JavaFX编程的实用手册。本书专为想要学习和提升JavaFX技术的专业人士设计，旨在帮助读者在JavaFX的世界里快速上手并创建高性能、交互式的用户界面。作者们在书中详尽地介绍了JavaFX开发的基础知识和关键概念，涵盖了从入门到高级应用的各个方面。第1章“Getting a Jump Start in JavaFX”引导读者踏上JavaFX开发之旅，从基础安装和配置开始，帮助他们理解JavaFX框架的核心理念。章节内容包括了设置环境、构建项目的基本步骤，以及如何编写第一个JavaFX应用程序。第二章“Creating a User Interface in JavaFX”着重于用户界面设计，讲解了如何使用JavaFX的控件、布局管理器和样式表来创建直观、响应式的界面元素。读者将学会如何构建美观且功能丰富的窗口、菜单、按钮等组件。第3章“Properties and Bindings”介绍了JavaFX中的属性绑定机制，它如何使应用程序的状态自动同步，这对于实现动态数据绑定和简化UI逻辑至关重要。这一章涵盖了数据模型与视图的交互，以及如何通过事件驱动来更新UI。第四章“Building Dynamic UI Layouts in JavaFX”深入探讨了如何根据用户操作和数据变化动态调整布局，确保应用程序的灵活性和可扩展性。读者将掌握响应式布局和网格布局的使用技巧。第五章“Using the JavaFX UI Controls”涵盖了JavaFX提供的各种内置控件，如文本框、列表框、滑块等，以及如何定制这些控件以满足特定需求。控制组件的事件处理和状态管理也是本章的重点内容。第六章“Collections and Concurrency”涉及集合框架和并发编程，帮助开发者理解和利用JavaFX的并发特性，优化多线程应用性能，避免常见的并发问题。第七章“Creating Charts in JavaFX”展示了如何使用JavaFX的数据可视化工具创建动态图表，这对于数据分析和展示来说是非常有用的。这章包含图表类型的选择、数据绑定和动画效果的实现。第八章“Using the Media Classes”讲述了如何在JavaFX中处理音频和视频，包括加载、播放和交互操作，以及媒体资源的管理。第九章“Accessing Web Services”介绍了JavaFX如何与Web服务进行交互，包括RESTful API的调用、JSON和XML数据处理，以及安全性和性能优化。第十章“JavaFX Languages and Markup”探讨了JavaFX对HTML、CSS和JavaScript的集成，使得开发者可以充分利用Web技术增强用户体验。附录部分深入剖析了Visage语言，这是一种用于描述JavaFX界面的声明式语言，可以帮助开发者更高效地构建复杂UI。总结起来，《Pro-Java-FX-2》不仅提供了全面的教程，还包含了实践项目和案例分析，适合希望通过JavaFX技术提升客户端应用开发能力的开发者阅读。随着JavaFX的发展，此书将始终紧跟最新趋势，帮助读者在这个充满活力的领域中大展拳脚。

CHAPTER 1 ■ GETTING A JUMP START IN JAVAFX

13

javafx.scene.image package and the Group class in the javafx.scene package. In both cases, they inherit

from the Node class.

■ Tip We can’t emphasize enough the importance of having the JavaFX API documentation handy while

reading this book. As classes, variables, and functions are mentioned, it’s often a good idea to look at the

documentation to get more information. In addition, this habit helps you become more familiar with what is

available to you in the API.

Displaying Images

As shown in the following code, displaying an image entails using an ImageView instance in conjunction

with an Image instance.

ImageViewBuilder.create()

.image(new Image("http://projavafx.com/images/earthrise.jpg"))

.build(),

The Image instance identifies the image resource and loads it from the URL assigned to its URL

variable. Both of these classes are located in the javafx.scene.image package.

Working with Graphical Nodes as a Group

One powerful graphical feature of JavaFX is the ability to create scene graphs, which consist of a tree of

graphical nodes. You can then assign values to properties of a Group located in the hierarchy, and the

nodes contained in the Group will be affected. In our current example from Listing 1-1, we’re using a

Group to contain a Text node and to clip a specific rectangular region within the Group so that the text

doesn’t appear on the moon or the Earth as it animates upward. Here’s the relevant code snippet:

GroupBuilder.create()

.layoutX(50)

.layoutY(180)

.children(

textRef

)

.clip(

RectangleBuilder.create()

.width(430)

.height(85)

.build()

)

.build()

Notice that the Group is located 50 pixels to the right and 180 pixels down, from where it would have

been located by default. This is due to the values assigned to the layoutX and layoutY variables of the

Group instance. Because this Group is contained directly by the Scene, its upper-left corner’s location is

CHAPTER 1 ■ GETTING A JUMP START IN JAVAFX

15

The layoutX and layoutY properties of the Group just described are examples of our earlier

statement that nodes contained in a Group will be affected by values assigned to properties of the

Group. Another example is setting the opacity property of a Group instance to 0.5, which causes all of

the nodes contained in that Group to become translucent. If the JavaFX API documentation is handy,

look at the properties available in the javafx.scene.Group class. Then look at the properties available in

the javafx.scene.Node class properties, which is where you’ll find the layoutX, layoutY, and opacity

variables that are inherited by the Group class.

Drawing Text

In the previous snippet, notice that several variables are available in the Text class. This particular

example is a little more complicated than the normal use of the Text class. Let’s first look at a typical

case, shown in the following snippet, in which you simply want to draw a string of text characters

somewhere in the scene.

TextBuilder.create()

.layoutX(65)

.layoutY(12)

.textOrigin(VPos.TOP)

.fill(Color.WHITE)

.text("Audio Configuration")

.font(Font.font("SansSerif", FontWeight.BOLD, 20))

.build(),

This snippet, borrowed from the Audio Configuration example in Figure 1-7 and Listing 1-3 later in

this chapter, draws the graphical Text string “Audio Configuration” in a bold Sans Serif font. The font

size is 20, and the color of the text is white.

Referring again to the JavaFX API documentation, notice that the VPos enum (in the javafx.geometry

package) has fields that serve as constants, for example, BASELINE, BOTTOM, and TOP. These control

the origin of the text with respect to vertical locations on the displayed Text:

• The TOP origin, as we’re using it in the previous code snippet, places the top of the

text (including ascenders) at the layoutY position, relative to the co-ordinate space

in which the Text is located.

• The BOTTOM origin would place the bottom of the text, including descenders

(located in a lowercase “g”, for example) at the layoutY position.

• The BASELINE origin would place the baseline of the text (excluding descenders)

at the layoutY position. This is the default value for the textOrigin property of a

Text instance.

While you’re looking at the javafx.scene.text package in the API documentation, take a look at the

font function of the Font class, which is used in the previous snippet to define the font family, weight,

and size of the Text.

CHAPTER 1 ■ GETTING A JUMP START IN JAVAFX

16

Turning back again to the Hello Earthrise example in Listing 1-1, we’re using some additional

properties of the Text class that enable it to flow from one line to the next:

• The wrappingWidth property enables you to specify at what number of pixels the

text will wrap.

• The textAlignment property enables you to control how the text will be justified. In

our example, TextAlignment.JUSTIFY aligns the text on both the left and right

sides, expanding the space between words to achieve that.

The text that we’re displaying is sufficiently long to wrap and be drawn on the Earth, so we need to

define a rectangular region outside of which that text can’t be seen.

Clipping Graphical Areas

To define a clipping area, we assign a Node subclass to the clip property that defines the clipping shape,

in this case a Rectangle that is 430 pixels wide and 85 pixels high. In addition to keeping the Text from

covering the moon, when the Text scrolls up as a result of animation the clipping area keeps the Text

from covering the earth.

Animating the Text to Make It Scroll Up

When the HelloEarthriseMain program is invoked, the Text begins scrolling up slowly. To achieve this

animation, we’re using the TranslateTransition class located in the javafx.animation package, as shown

in the following snippet from Listing 1-1.

TranslateTransition transTransition = TranslateTransitionBuilder.create()

.duration(new Duration(75000))

.node(textRef)

.toY(-820)

.interpolator(Interpolator.LINEAR)

.cycleCount(Timeline.INDEFINITE)

.build();

...code omitted...

// Start the text animation

transTransition.play();

The javafx.animation package contains convenience classes for animating nodes. This

TranslateTransition instance (created by the TranslateTransitionBuilder class) translates the Text node

referenced by the textRef variable from its original Y position of 100 pixels to a Y position of –820 pixels,

over a duration of 75 seconds. The Interpolator.LINEAR constant is assigned to the interpolator

property, which causes the animation to proceed in a linear fashion. A look at the API docs for the

Interpolator class in the javafx.animation package reveals that there are other forms of interpolation

available, one of which is EASE_OUT, which slows down the animation toward the end of the specified

duration.

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