Class LayerTree

  • public class LayerTree
extends java.lang.Object

    This class was built using the Chrome Remote Dev-Tools A.P.I., which is specified by two JSON-RPC Files. These files were obtained from the Chrome Dev Tools Protocol Git Hub Page, which has a "Tip of Tree" (the latest) API-Specification Page Here: JSON-RPC Protocol Specification.

    These files were converted into this Java-Browser (CDP) Library. The intention is to have them function in a similar fasion to the Node.js Tool known as 'Puppeteer', Microsoft's 'Playwright' and of course the Main-Stay 'Selenium.' The Java-HTML JAR Library merely implements the Java Types & Commands defined by Google's DevTools Protocol.

    🧠 View the Google CDP API:

    [No Description Provided by Google]

    The top-level description and explanation for this class (this comment, at the top this Java-Doc Page) is repeated, verbatim, across all of the domain classes which comprise Google's CDP API.

    This class is intended to be used with a Browser Instance

    These methods have been tested, to some degree, using Google Chrome. In order to use this class you must start a web-browser instance and make a connection to the browser using a Remote Debugging Port. Google-Corporation is the developer of this API, but any browser which accepts a Remote Debug Port Connection over Web-Sockets.

    Google-Chrome was used during the development process of the classes in this particular package. Lately, it has been asserted Microsoft has switched to using the Chrome Browser-Engine for its Microsoft Edge Internal Code-Base. Therefore, there may some functionality available when running the methods in this class with Microsoft-Edge.

    Check whether the your Web-Browser will allow itself to be driven by the Web-Socket RDP-Port 9223. See the examples available in package Torello.Browser to undertand how to build a PageConn and BrowserConn Web-Socket Connection, and how to build a WebSocketSender instance in order to execute the methods in this class.

    Web-Socket & JSON API:   
    Every one of the methods that reside in this class are designed to do nothing more than:

    1. Accept Parameters from the User, and "Marshall Them" into a Valid JSON-Request
    2. Transmit the Marshalled Request-JSON to a Headless Web-Browser over a Web-Socket Connection
    3. Receive BOTH that Command-Results AND any Browser Event-Firings from the Web-Socket
    4. Parse JSON Method-Results and Browser-Event Firings, and Subsequently Convert them to Standard Java-Types
    5. Report these Method-Results and Browser-Events to the User via a User-Registered, Event-Listener (Events) or a Promise Object (Command Responses / Results)

    Unlike the bulk of the Java HTML JAR Library, there is very little native Java-Code, and very little testing that may be done on any of the classes & methods in this package. The code inside these classes does nothing more than marshall-and-unmarshall Java-Types into Json-Requests (and vice-versa). The Java-Script & Browser modules inside of a Google-Chrome instance are, theoretically, handling these requests, and returning their results (or events) over the Web-Socket Connection.

    It has been asserted (by Google Chrome Developers) that some of these methods are only "partially working" or "experimental".


    Asking Chat-GPT for Help:   
    The LLM otherwise known as "Chat-GPT" does, indeed, have an expert level of knowledge about the "Remote DevTools Protocol". The API that the Chrome DevTools Protocl (CDP) exports is extremely well understood by the LLM, and generally I have found that Chat-GPT understands (by 2 or 3 orders of magnitude) better what my Auto-Generated JSON-Wrappers can do in controlling a Web-Browser than I could ever possibly hope to understand.

    Though not available today, there will soon be an automatically downloadable Token-Stream (AI Embeddings) BUTTON available on my Java-Doc Pages that should hopefully make it extremely easy to post my code-base, RAG Style, to Chat-GPT and other LLM's when 'interogating' them. Presently, because my "Get Token Stream Button" does not exist yet on any of my pages, what you can do is copy-and-paste any Method-Signature from any one of these pages and then ask Chat-GPT to explain what that Browser or Java-Script Function is actually doing. It is very likely to give you some pretty neat answers.

    I have found that every single one of the Domains, Types & Events which are offered by the CDP Protocol (though not documented very well by Google), are perfectly understood by the A.I. LLM - literally to the point where it does know (much better than I ever could) what my own code base actually does!

    Try it out, it's a lot of fun. Note that this package and these classes were originally developed solely to be able to execute the Java-Script that a browser executes when visiting a Web-Site. Complete HTML-Page Content can be scraped (using the HTML Data-Scraping Tools in Java-HTML) off of Web-Sites that have dynamic / Java-Script Generated Content.


    Conspicuous Boxed-Types Usage:
    You may notice that there are many methods that have parameters which accept, for instance, an Integer, instead of a primitive int. Just to remind the readiner, in Java Programs a Boxed Type is a standard Java-Primitive which has been converted into an Object-Reference. The use of Boxed-Types in this code base is an easy-and-fast-way to allow for the concept of "Optional Parameters" or "Optional Field Value."

    Whenever you see a method that accepts an Integer, the reason for this Parameter-Type choice is actually to allow a user to pass 'null' to it. This is a simple way to ELIDE passing any value at all to parameters which Google-Chrome would otherwise assert are "Optional." Whenever you pass 'null' to a Boxed-Types in this class, the Json-Processor will simply eliminate that Object-Property from the command altogether; and the browser will simply not receive any value for that parameter when that command is invoked.

    The Java Language Specification does not have an easy or well defined means of accepting optional method parameters; so Boxed-Types and 'null' are utilized here. Note that 'null' may be passed to any Command Method-Parameter that is listed as Optional on the Java-Doc Page description for that parameter.



    Stateless Class:
    This class neither contains any program-state, nor can it be instantiated. The @StaticFunctional Annotation may also be called 'The Spaghetti Report'. Static-Functional classes are, essentially, C-Styled Files, without any constructors or non-static member fields. It is a concept very similar to the Java-Bean's @Stateless Annotation.

    • 1 Constructor(s), 1 declared private, zero-argument constructor
    • 9 Method(s), 9 declared static
    • 3 Field(s), 3 declared static, 3 declared final


    • Nested Class Summary

       
      Type Nested Classes: Types / Classes that Are Used & Exported by this Domain
      Modifier and Type Class Description
      static class  LayerTree.Layer
      Information about a compositing layer.
      static class  LayerTree.PictureTile
      Serialized fragment of layer picture along with its offset within the layer.
      static class  LayerTree.ScrollRect
      Rectangle where scrolling happens on the main thread.
      static class  LayerTree.StickyPositionConstraint
      Sticky position constraints.
       
      Event Nested Classes: Browser Events, as Java Inner Classes, Which are Fired by this Domain
      Modifier and Type Class Description
      static class  LayerTree.layerPainted
      [No Description Provided by Google]
      static class  LayerTree.layerTreeDidChange
      [No Description Provided by Google]
       
      Command-Returns Nested Classes: Domain-Commands with Multiple Return-Values, and a Dedicated Inner-Class
      Modifier and Type Class Description
      static class  LayerTree.compositingReasons$$RET
      Provides the reasons why the given layer was composited.

    • Field Summary

       
      Eliminated Types: Removed CDP Types which Have Been Re-Mapped to Basic Java String Constants
      Modifier and Type Field Description
      static String LayerId
      Unique Layer identifier.
      static String PaintProfile
      Array of timings, one per paint step.
      static String SnapshotId
      Unique snapshot identifier.

    • Field Detail

      • LayerId

        🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static final java.lang.String LayerId
        Unique Layer identifier.

        The Type LayerId has been eliminated, because it is a direct mapping to a basic Java-Type; it has no additional fields, or other distinguishing properties. Instead, this CDP defined type has been relegated to a simple String Constant, for documentation & reference purposes only.

        The code which is generated which employs this type replaces its use with the Standard Java-Type: String

        Eliminated Type
        See Also:
        Constant Field Values

      • PaintProfile

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static final java.lang.String PaintProfile
        Array of timings, one per paint step.

        The Type PaintProfile has been eliminated, because it is a direct mapping to a basic Java-Type; it has no additional fields, or other distinguishing properties. Instead, this CDP defined type has been relegated to a simple String Constant, for documentation & reference purposes only.

        The code which is generated which employs this type replaces its use with the Standard Java-Type: Number

        Eliminated Type
        See Also:
        Constant Field Values

      • SnapshotId

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static final java.lang.String SnapshotId
        Unique snapshot identifier.

        The Type SnapshotId has been eliminated, because it is a direct mapping to a basic Java-Type; it has no additional fields, or other distinguishing properties. Instead, this CDP defined type has been relegated to a simple String Constant, for documentation & reference purposes only.

        The code which is generated which employs this type replaces its use with the Standard Java-Type: String

        Eliminated Type
        See Also:
        Constant Field Values

    • Method Detail

      • disable

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> disable()
        Disables compositing tree inspection.
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • enable

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> enable()
        Enables compositing tree inspection.
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • loadSnapshot

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.String> loadSnapshot​
            (LayerTree.PictureTile[] tiles)
        Returns the snapshot identifier.
        Parameters:
        tiles - An array of tiles composing the snapshot.
        Returns:
        An instance of Script<String>

        This script may be executed, using Script.exec, and afterwards, a Promise <String> will be returned

        Finally, the Promise may be awaited, using Promise.await(), and the returned result of this Browser Function may be retrieved.

        This Browser Function's Promise returns: String (snapshotId)
        The id of the snapshot.

      • makeSnapshot

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.String> makeSnapshot​
            (java.lang.String layerId)
        Returns the layer snapshot identifier.
        Parameters:
        layerId - The id of the layer.
        Returns:
        An instance of Script<String>

        This script may be executed, using Script.exec, and afterwards, a Promise <String> will be returned

        Finally, the Promise may be awaited, using Promise.await(), and the returned result of this Browser Function may be retrieved.

        This Browser Function's Promise returns: String (snapshotId)
        The id of the layer snapshot.

      • profileSnapshot

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Number[]> profileSnapshot​
            (java.lang.String snapshotId,
             java.lang.Integer minRepeatCount,
             java.lang.Number minDuration,
             DOM.Rect clipRect)
        [No Description Provided by Google]
        Parameters:
        snapshotId - The id of the layer snapshot.
        minRepeatCount - The maximum number of times to replay the snapshot (1, if not specified).
        OPTIONAL
        minDuration - The minimum duration (in seconds) to replay the snapshot.
        OPTIONAL
        clipRect - The clip rectangle to apply when replaying the snapshot.
        OPTIONAL
        Returns:
        An instance of Script<Number[]>

        This script may be executed, using Script.exec, and afterwards, a Promise <Number[]> will be returned

        Finally, the Promise may be awaited, using Promise.await(), and the returned result of this Browser Function may be retrieved.

        This Browser Function's Promise returns: Number[] (timings)
        The array of paint profiles, one per run.

      • releaseSnapshot

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.Void> releaseSnapshot​
            (java.lang.String snapshotId)
        Releases layer snapshot captured by the back-end.
        Parameters:
        snapshotId - The id of the layer snapshot.
        Returns:
        An instance of Script<Void>

        This Script instance must be executed before the browser receives the invocation-request.

        This Browser-Function does not have a return-value. You may choose to await the Promise<Void> to ensure that the Browser Function has run to completion.

      • replaySnapshot

        🡅  🡇  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<java.lang.String> replaySnapshot​
            (java.lang.String snapshotId,
             java.lang.Integer fromStep,
             java.lang.Integer toStep,
             java.lang.Number scale)
        Replays the layer snapshot and returns the resulting bitmap.
        Parameters:
        snapshotId - The id of the layer snapshot.
        fromStep - The first step to replay from (replay from the very start if not specified).
        OPTIONAL
        toStep - The last step to replay to (replay till the end if not specified).
        OPTIONAL
        scale - The scale to apply while replaying (defaults to 1).
        OPTIONAL
        Returns:
        An instance of Script<String>

        This script may be executed, using Script.exec, and afterwards, a Promise <String> will be returned

        Finally, the Promise may be awaited, using Promise.await(), and the returned result of this Browser Function may be retrieved.

        This Browser Function's Promise returns: String (dataURL)
        A data: URL for resulting image.

      • snapshotCommandLog

        🡅  ⇈  ⮫ 🗕  🗗  🗖 
        public static Script<JsonValue> snapshotCommandLog​
            (java.lang.String snapshotId)
        Replays the layer snapshot and returns canvas log.
        Parameters:
        snapshotId - The id of the layer snapshot.
        Returns:
        An instance of Script<JsonValue>

        This script may be executed, using Script.exec, and afterwards, a Promise <JsonValue> will be returned

        Finally, the Promise may be awaited, using Promise.await(), and the returned result of this Browser Function may be retrieved.

        This Browser Function's Promise returns: JsonValue (commandLog)
        The array of canvas function calls.