javafx官方文檔學習之二Control體系學習之架構理解

時間 2019-11-20

標籤 javafx 官方文檔學習之二 control 體系架構理解欄目 Java 简体版

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Package javafx.scene.control

Control基類及其繼承者。是主要的與用戶交互的UI組件。java

1、接口篇。app

Control實現了Skinnable接口，這個Skinnable接口就是能夠用皮膚渲染組件的標誌，實現它使組件能夠自由地更換各類皮膚成爲可能，這裏只說是可能，由於還須要一個類Skin--皮膚的表明。能夠這樣理解誒一個Control組件就是一個Skinnable，而後須要Skin來提供渲染的皮膚。ide

Skinnable接口主要有如下方法：this

`Skin<?>`	`getSkin()` Returns the skin that renders this `Control`lua
`void`	`setSkin(Skin<?> value)` Sets the skin that will render this `Control`spa
`ObjectProperty<Skin<?>>`	`skinProperty()` Skin is responsible for rendering this `Control`..net

Skin皮膚接口定義瞭如何獲取皮膚的方法。皮膚Skin也須要用一個Node來提供皮膚外觀。
code

public interface Skin<C extends >

`void`	`dispose()` Called by a Skinnable when the Skin is replaced on the Skinnable.對象
`Node`	`getNode()` Gets the Node which represents this Skin.繼承
`C`	`getSkinnable()` Gets the Skinnable to which this Skin is assigned.

Interface TextInputControl.Content

這個接口就是文本輸入內容的表明。Interface representing a text input's content.Since it is an ObservableStringValue, you can also bind to, or observe the content.他是一個能夠被觀察的字符串文本值對象。你經過它能夠綁定或者觀察該文本內容的變化。

`void`	`delete(int start, int end, boolean notifyListeners)` Removes a sequence of characters from the content.
`java.lang.String`	`get(int start, int end)` Retrieves a subset of the content.
`void`	`insert(int index, java.lang.String text, boolean notifyListeners)` Inserts a sequence of characters into the content.
`int`	`length()` Returns the number of characters represented by the content.

它的父類有：

All Superinterfaces:
Observable, ObservableObjectValue<java.lang.String>, ObservableStringValue, ObservableValue<java.lang.String>

Observable:在javafx.beans中，An Observable is an entity that wraps content and allows to observe the content for invalidations.An implementation of Observable may support lazy evaluation, which means that the content is not immediately recomputed after changes, but lazily the next time it is requested（他並不在改變後立刻進行驗算，只是在請求時才驗算，這就是懶驗真。）

`void`	`addListener(InvalidationListener listener)` Adds an `InvalidationListener` which will be notified whenever the `Observable` becomes invalid.
`void`	`removeListener(InvalidationListener listener)` Removes the given listener from the list of listeners, that are notified whenever the value of the `Observable` becomes invalid.

javafx.beans.value

InvalidationListener

An InvalidationListener is notified whenever an ObservableValue becomes invalid. It can be registered and unregistered with Observable.addListener(InvalidationListener) respectively Observable.removeListener(InvalidationListener)

For an in-depth explanation of invalidation events and how they differ from change events, see the documentation of ObservableValue.

The same instance of InvalidationListener can be registered to listen to multiple ObservableValues.

InvalidationListener主要用於監聽ObservableValue（能夠監聽的值對象），它只是在值無效的時候被通知。

須要實現如下方法：

void

invalidated(Observable observable)

This method needs to be provided by an implementation of InvalidationListener.

javafx.beans.value

Interface ObservableValue<T>

ObservableValue是Observable的子類。

通常狀況相愛咱們無須直接實現這個類，而是經過繼承它的子類來實現自定義附加功能

The value of the ObservableValue can be requested with getValue().

咱們可使用ObservableValue來監聽到兩種Value Change Event，一個是Value Change,一個是Value invadidation.能夠經過InvalidationListener和ChangeListener來進行監聽。

因爲繼承了Observale接口故而，它支持懶驗證模式。

An implementation of ObservableValue may support lazy evaluation

Important note: attaching a ChangeListener enforces eager computation even if the implementation of the ObservableValue supports lazy evaluation.

雖然支持懶驗證模式，可是若是你附加一個ChangeListener到這個上面，這會致使懶驗證失效，由於它不得不在每次值改變時進行提交驗算通知ChangeListener，而這會致使大量的無謂消耗，因此除非確實有很是迫切的必要，不然不要破壞這種懶驗證模式。

`void`	`addListener(ChangeListener<? super T> listener)` Adds a `ChangeListener` which will be notified whenever the value of the `ObservableValue` changes.
`T`	`getValue()` Returns the current value of this `ObservableValue`
`void`	`removeListener(ChangeListener<? super T> listener)` Removes the given listener from the list of listeners, that are notified whenever the value of the `ObservableValue` changes.

javafx.beans.value

Interface ChangeListener<T>

實現它要覆蓋：

void

changed(ObservableValue<? extends T> observable, T oldValue, T newValue)

This method needs to be provided by an implementation of ChangeListener.

好了如今回到咱們的TextInputControl.Content

它實現了ObservableStringValue類，而這個類有

javafx.beans.value

Interface ObservableStringValue

All Superinterfaces:
Observable, ObservableObjectValue<java.lang.String>, ObservableValue<java.lang.String>

TextInputControl.Content

Interface representing a text input's content. Since it is an ObservableStringValue, you can also bind to, or observe the content.

這個表明了咱們的文本輸入內容，可是它能夠綁定文本內容，監聽文本內容的變化和有效性。

`void`	`delete(int start, int end, boolean notifyListeners)` Removes a sequence of characters from the content.
`java.lang.String`	`get(int start, int end)` Retrieves a subset of the content.
`void`	`insert(int index, java.lang.String text, boolean notifyListeners)` Inserts a sequence of characters into the content.
`int`	`length()` Returns the number of characters represented by the content.

addListener,removeListener,getValue等方法均繼承ObservableValue接口addListener, getValue, removeListener

下面咱們來說

Toggle開關接口：

javafx.scene.control

Interface Toggle

All Known Implementing Classes:
RadioButton, RadioMenuItem, ToggleButton

Represents a control that can be toggled between selected and non-selected states. In addition, a Toggle can be assigned a ToggleGroup, which manages all assigned Toggles such that only a single Toggle within the ToggleGroup may be selected at any one time.

Toggle表明着單選或者開關狀態，它是RadioButton，RadioMenuItem，ToggleButton的實現接口。使用時須要注意與ToggleGroup一塊兒使用，

這相似與Swing裏面的RadioButton和RadioButtonGroup的關係，須要使用ToggleGroup來組成和管理一個單選組或開關組使之這個組裏只能有一個組件狀態能夠改變。

`ObservableMap<java.lang.Object,java.lang.Object>`	`getProperties()` Returns an observable map of properties on this toggle for use primarily by application developers.
`ToggleGroup`	`getToggleGroup()` Returns The `ToggleGroup` to which this `Toggle` belongs.
`java.lang.Object`	`getUserData()` Returns a previously set Object property, or null if no such property has been set using the `Node.setUserData(java.lang.Object)` method.
`boolean`	`isSelected()` Indicates whether this `Toggle` is selected.
`BooleanProperty`	`selectedProperty()` The selected state for this `Toggle`.
`void`	`setSelected(boolean selected)` Sets this `Toggle` as selected or unselected.
`void`	`setToggleGroup(ToggleGroup toggleGroup)` Sets the `ToggleGroup` to which this `Toggle` belongs.
`void`	`setUserData(java.lang.Object value)` Convenience method for setting a single Object property that can be retrieved at a later date.
`ObjectProperty<ToggleGroup>`	`toggleGroupProperty()` The `ToggleGroup` to which this `Toggle` belongs.

-----------------

ToggleGroup

`Toggle`	`getSelectedToggle()` Gets the selected `Toggle`.
`ObservableList<Toggle>`	`getToggles()` The list of toggles within the ToggleGroup.
`ReadOnlyObjectProperty<Toggle>`	`selectedToggleProperty()` The selected toggle.
`void`	`selectToggle(Toggle value)` Selects the toggle.