Skip to content

Latest commit

 

History

History
92 lines (67 loc) · 2.86 KB

embedding.rst

File metadata and controls

92 lines (67 loc) · 2.86 KB
Raw

Browsing Context Embedding

Embedder Element to nsDocShell

In order to render the contents of a BrowsingContext, the embedding element needs to be able to communicate with the nsDocShell which is currently being used to host it's content. This is done in 3 different ways depending on which combination of processes is in-use.

  • in-process: The nsFrameLoader directly embeds the nsDocShell.
  • remote tab: The parent process is the embedder, and uses a PBrowser, via a BrowserHost. The BrowserChild actor holds the actual nsDocShell alive.
  • remote subframe: A content process is the embedder, and uses a PBrowserBridge, via a BrowserBridgeHost to communicate with the parent process. The parent process then uses a BrowserParent, as in the remote tab case, to communicate with the nsDocShell.

Diagram

.. digraph:: embedding

  node [shape=rectangle]

  subgraph cluster_choice {
    color=transparent;
    node [shape=none];

    "In-Process";
    "Remote Tab";
    "Remote Subframe";
  }

  "nsFrameLoaderOwner" [label="nsFrameLoaderOwner\ne.g. <iframe>, <xul:browser>, <embed>"]

  "nsFrameLoaderOwner" -> "nsFrameLoader";

  "nsFrameLoader" -> "In-Process" [dir=none];
  "nsFrameLoader" -> "Remote Tab" [dir=none];
  "nsFrameLoader" -> "Remote Subframe" [dir=none];

  "In-Process" -> "nsDocShell";
  "Remote Tab" -> "BrowserHost";
  "Remote Subframe" -> "BrowserBridgeHost";

  "BrowserHost" -> "BrowserParent";
  "BrowserParent" -> "BrowserChild" [label="PBrowser" style=dotted];
  "BrowserChild" -> "nsDocShell";

  "BrowserBridgeHost" -> "BrowserBridgeChild";
  "BrowserBridgeChild" -> "BrowserBridgeParent" [label="PBrowserBridge", style=dotted];
  "BrowserBridgeParent" -> "BrowserParent";

nsDocShell to Document

Embedding an individual document within a nsDocShell is done within the content process, which has that docshell.

Diagram

This diagram shows the objects involved in a content process which is being used to host a given BrowsingContext, along with rough relationships between them. Dotted lines represent a "current" relationship, whereas solid lines are a stronger lifetime relationship.

.. graph:: document

  node [shape=rectangle]

  "BrowsingContext" -- "nsDocShell" [style=dotted];
  "nsDocShell" -- "nsGlobalWindowOuter";
  "nsGlobalWindowOuter" -- "nsGlobalWindowInner" [style=dotted];
  "nsGlobalWindowInner" -- "Document" [style=dotted];

  "nsDocShell" -- "nsDocumentViewer" [style=dotted];
  "nsDocumentViewer" -- "Document";
  "nsDocumentViewer" -- "PresShell";

  "nsGlobalWindowInner" -- "WindowGlobalChild";
  "BrowsingContext" -- "WindowContext" [style=dotted];
  "WindowContext" -- "nsGlobalWindowInner";

  subgraph cluster_synced {
    label = "Synced Contexts";
    "BrowsingContext" "WindowContext";
  }