SplitView Proposed Architecture
Refactoring Brackets to Support Split View with Multiple Documents requires quite a bit of hacking on the plumbing but there are only a few places that need to be heavily refactored to do so. To break this work up in to smaller pieces, an accompanying document SplitView Architecture Tasking has been created.
This proposal calls for anything that wants to show a view in the "Editor Workspace Area" must be a Registered View Provider. There are other ways to get views into this area but deserialization requires a method for views to be reconstructed at startup and this is done through a Registered View Provider. Registered View Providers expose methods to create a view for a given URI. A ViewFactory will be responsible for maintaining the View Provider registry and invoke the Registered View Provider's createView method when a Registered View Provider indicates that it can create a viewer for a given URI.
Initially there will be 2 Registered View Providers: an Image View Provider and a Document Editor provider. EditorManager will be the Registered View Provider for creating all document editors.
Workingset management moves from DocumentManager to MainViewManager -- although some legacy APIs, Events, Functions, Commands, etc..., will remain for some time to maintain backwards compatibility. The concept of Workingset is going away and all Workingset APIs are going to be renamed PaneViewList and WorkingSetView is renamed PaneViewListView.
Those items that are needed to maintain backwards compatibility have been identified and documented in the SplitView Extension Migration Guide and are detailed in the section below on Deprecating Legacy APIs
This proposal is an overview of the system along with functional details and implementation changes needed to build the SplitView feature.
These EditorManager APIs that exist will remain for backwards compatibility and convenience but their implementation will move as described.
Reimplemented by moving the current implementation into Editor and invoking Editor.getFocusedEditor() for the Editor object of the focused pane. The API will continue to work as it does today.
Reimplemented by moving the current implementation into Editor and invoking Editor.getCurrentlyViewedPath for the Editor object of the focused pane. The API will continue to work as it does today.
Reimplemented by moving the current implementation into Editor and invoking EditorManager.getFocusedEditor().getCurrentFullEditor() The API will continue to work as it does today.
This API will change the layout to match rows and columns.
Update pane height/width.
This is how the viewFactory will add views to the layout but components can add views as necessary by calling addView and passing it the relevant data. This gives the framework the flexibility to be able to create arbitrary views on the fly without a URI. Calling this method directly, however, means that deserialization will not be able to reconstruct the view since there is no factory method for doing so. See MainViewManager.registerViewProvider() to register a view provider so that views can be reconstructed during the deserialization process.
This method will return a viewID that is used to address the view.
view is an object with the following interface:
/** @type {string} **/
var title;
/** @type {boolean} **/
var modified;
function getUI();
/** @returns {{!jQueryObject}} **/provder is an object with the following interface:
/** @type {string} **/
var displayname;
function canDecode(uri)
/** @returns {boolean} **/
function createViweFor(uri)
/** @return {!jQueryObject} **/Call this when the view's title has changed and you need to update it in the workingset and titlebar of the application.
Removes a view from the pane and PaneViewList.
This will return any context data associated with the view when it was created
The Implementation of these functions will move from DocumentManager to MainViewManager. See the section at the bottom of this document for a list of deprecated Workingset APIs that need to be kept for backwards compatibility.
Moving this functionality to MainViewManager is being done primarily because each view pane will have its own PaneViewList and MainViewManager manages the view panes so it makes sense to move it there. But, architecturally, it makes sense that this list is a property of the view because it's really a UI structure.
Extension Authors and 3rd party developers are encouraged to use other methods whenever possible to work with the set of open documents. See the SplitView Extension Migration Guide and the section below on Workingset Alternatives for more information.
PaneViewList APIs will replace the WorkingSet APIs and their implementation will be migrated from DocumentManager. Some of the WorkingSet APIs will continue to exist in DocumentManager to maintain backwards compatibility. The PaneViewList APIs have the same functionality as the Workingset APIs from previous versions of Brackets except they will take a paneId to identify which PaneViewList to work on.
Most of the PaneViewList APIs will take one of these Special Pane IDs for paneId in addition to valid paneIds:
------------------------+-----------------------------------------------------------------------------------------------------
Constant | Usage
------------------------+-----------------------------------------------------------------------------------------------------
ALL_PANES | Perform the operation on all panes (e.g. search for fullpath in all Pane View Lists)
FOCUSED_PANE | Perform the operation on the currently focused pane (can also use MainViewManager.getFocusedPane())
------------------------+-----------------------------------------------------------------------------------------------------
Returns {paneId: paneId, index: index) or undefined if not found
MainViewManager Events will add paneId to event data
provided for backwards compatibility but adds PaneId as Event Data
The initial implementation will be mostly handled by MainViewManager but a MainViewLayoutManager object will be created just to help handle the layout. We shouldn't need to build for advanced layout mechanics since we only need, at most, 2 panes. Support for arbitrary rows and columns can be built into the MainViewLayoutManager builder at a later date.
Whether or not the initial implementation uses a MainViewLayoutManager object is an implementation detail that will be decided when the feature is implemented.
Layout Rules:
- Only 1 pane or 1 row and 2 columns or 2 rows and 1 column are initially supported
- Panes, when created, will initially show the Brackets logo interstitial screen until the corresponding view for that pane has loaded its content.
- When a pane is destroyed, all views in the corresponding
PaneViewListfor that pane are moved to another pane and that pane'sPaneViewListis updated. Since there are, at most, 2 panes in the initial implementation, this is just a matter of combining theViewPaneListwith the remaining Pane'sViewPaneList. This will generate aviewPaneListRemoveListevent is generated for the pane losing views and a correspondingviewPaneListAddListevent is generated for the pane who is receiving the the views.
Each Views HTML is rendered at runtime and inserted it into the DOM by the PaneViewManager. The Editor Instance will generate the HTML when the EditorManager asks for it and insert it into the DOM in the appropriate place to ensure proper z-order. The generated HTML can either come from a template rendered with Mustache or simple jQuery insertion. This is the same process for any RegisteredViewProvider.
MainViewManager will handle the WorkspaceManager's resize event and create a MainViewLayoutManager object to assist with the layout.
WorkspaceManager computes the new size of #editor-holder in its the window.resize event handler and triggers an event to resize that the MainViewManager object subscribes to. Currently WorkspaceManager only computes the Height and passes that as data but it needs to also compute Width and pass that as well so that the MainViewLayoutManager object can verify that the editor holder doesn't get too narrow to handle 2 editor instances. At the point that it is too narrow then it will need to start resizing other columns to get a decent layout. This algorithm becomes more complex with more columns and rows. For now it can be a matter of going to something like 50%. We may want to bump up the shell's minimum width as well to avoid getting too small.
height and width are expressed in percentages when affixing the CSS to the columns (e.g. width: 40%). Doing it in a percentage and only applying to all except the rightmost column and bottom most row will yield a fluid layout. The API will reject setting the width on the rightmost column. For the initial implementation we may just go with 50% splits all around without the ability to resize.
#Implementing Pane Management
ViewManager will manage a PaneViewList for each of its editor panes. This may be abstracted and delegated into a Pane object if implementation starts to get to messy but the API to get the PaneViewList will be on MainViewManager to make the interface easier to use. Management of the Workingset will move from the DocumentManager into ViewManager the and renamed as PaneViewList. The list will no longer be a collection of Document objects. It will be a collection of file names.
NOTE: To abstract the PaneViewList's location, each view pane is addressed by paneId rather than row,col. Valid paneId values cannot be false, 0, null, undefined or "" so that they can be used in truthy tests.
Clients can use the Special Pane IDs paneIds for PaneViewList APIs to avoid having to maintain a reference to the pane in which a view belongs.
PaneViewListView objects are created when the event viewPaneCreated is handled. SideBarView will handle this event and create a PaneViewListView object (which is bound to the pane's PaneViewList object) for the pane which passed as event data.
#open-files-container is a container which contains one or more .working-set-container divs in the DOM. Several 3rd Party Extensions rely or use the #open-files-container div. The extensions which style the elements will continue to work.
To support images in split view, we will need to change the rules to allow for images in PaneViewLists. This means that callers of the new PaneViewList APIs will need to check to ensure they can operate on a file by getting its file type from the language manager or by checking its extension.
PaneViewLists will basically just be a list of files that may or may not have a Document object owned by the DocumentManager. The deprecated API, DocumentManager.getWorkingSet(), will filter out any files that don't have an associated Document object.
This currently works by listening to contextmenu events on the #open_files_container. This will change to listen to contextmenu events on an .open_files_container and the PaneViewListView who attached to the .open_files_container will be maintain the paneId from the EventData it was passed during the create event so that callers (Extensions) will be able to determine which editor has focus when the menu is invoked.
This will also trigger a focus action on the DOM node causing the Editor to gain focus. The Default extension, CloseOthers, will be retooled to work on the PaneViewList for the editor pane associated with the PaneViewListView that manages it and ask that EditorManager instance for the PaneViewList.
DefaultMenus:
$("#open-files-container").on("contextmenu", function (e) {
working_set_cmenu.open(e);
});
Becomes:
$(".working-set-container").on("contextmenu", function (e) {
e.paneId = this._paneId;
working_set_cmenu.open(e);
});Although they aren't called Workingsets anymore, extensions making use of the WorkingSet APIs today are encouraged to migrate to these new convenience methods rather than just accessing ViewList directly if possible.
Returns a list of all open files
Returns a list of all open documents -- including documents which are in a PaneViewList but not yet opened, documents which have been opened in inline editors but not part of a PaneViewList and opened but not modified or added to any PaneViewList.
-------------------------------------+--------------------------------------------------------
API | Calls...
-------------------------------------+--------------------------------------------------------
DocumentManager.getCurrentDocument() | EditorManager
| .getFocusedEditor()
| .getDocument();
-------------------------------------+--------------------------------------------------------
DocumentManager.getWorkingSet() | $.map(ViewManager.getPaneViewList(ALL_PANES, …),
| function(fullPath) {
| if (DocumentManager.isDocument(fullPath)) {
| return fullPath;
| }
| });
-------------------------------------+--------------------------------------------------------
DocumentManager.findInWorkingSet() | return ViewManager
*only used by pflynn | .findInPaneViewList(ALL_PANES, ...).index || -1;
-------------------------------------+--------------------------------------------------------
DocumentManager.addToWorkingSet() | return ViewManager
| .addToPaneViewList(FOCUSED_PANE, ...);
-------------------------------------+--------------------------------------------------------
DocumentManager.addListToWorkingSet | return ViewManager
| .addListToPaneViewList(FOCUSED_PANE, ...);
-------------------------------------+--------------------------------------------------------
DocumentManager.removeFromWorkingSet | return ViewManager
| .removeFromPaneViewList(ALL_PANES, ...);
-------------------------------------+--------------------------------------------------------
The following Events will be kept on the DocumentManager object to maintain backwards compatibility but will just be a repub of the EditorManager events.
Fired when handling EditorManager.fullEditorChanged
Both WorkingSetView and PanelManager will need to be stubbed and deprecation warnings will be added to them when used.
The following EditorManager functions will move to Editor and are opportunistic refactorings since we're working in that code. These refactorings aid in the overall implementation but aren't necessary.
------------------------+-----------------------------------+-------------------------------------
Name | Usage | Disposition
------------------------+-----------------------------------+-------------------------------------
_openInlineWidget | Internal Inline Widget Management | Moves to Editor without impunity
------------------------+-----------------------------------+-------------------------------------
_toggleInlineWidget | Command Handler | Current Implementation moves to
| | Editor
| | Command handler will call
| | Editor
| | .getFocusedEditor()
| | .toggleInlineWidget()
------------------------+-----------------------------------+-------------------------------------
closeInlineWidget | | Moves to Editor
| | calls hostEditor.closeInlineWidget()
------------------------+-----------------------------------+-------------------------------------
getInlineEditors | | Moves to Editor
| | calls hostEditor.getInlineEditors()
------------------------+-----------------------------------+-------------------------------------
getFocusedInlineWidget | | Doesn't move but passes through to
| | getFocusedEditor()
| | .getFocusedInlineWidget();
------------------------+-----------------------------------+-------------------------------------
The following list of commands will move from DocumentCommandHandlers along with their corresponding implementation into a new module -- ViewCommandHandlers. We will also remove "file." from the command name and rename the commands to "cmd.", deprecating the old command ids in the same fashion the find commands were deprecated using getters.
Raw data can be found here: splitview architecture notes