AppCode 2020.2 Help

Differences viewer for files

Project tool window | context menu of a file | Compare File with Editor
Project tool window | context menu of a file | Compare Files
Version Control/Commit tool window | Local Changes tab | icons.actions.diff.png
Version Control tool window | context menu of a folder or file | Show Diff

This dialog is displayed when you compare two files or two versions of a file (local changes or changes between local files and their revisions in a remote repository). You can compare files of any types, including binaries and .jar files. To open the dialog, select two files to compare or a file to compare its versions and press ⌃D.

The differences viewer provides a powerful editor that enables code completion, live templates, etc.

Diff & Merge viewer

ItemTooltip and ShortcutDescription
the Previous Difference button/the Next Difference buttonPrevious Difference / Next Difference ⇧F7 F7

Use these buttons to jump to the next/previous difference.

When the last/first difference is reached, AppCode suggests to click the arrow buttons F7/⇧F7 once more and compare other files, depending on the Go to the next file after reaching last change option in the Differences Viewer settings.

This behavior is supported only when the Differences Viewer is invoked from the Version Control tool window ⌥9.

the Back button
the Forward button
Compare Previous/Next File

Click these buttons to compare the local copy of the previous/next file with its update from the server.

the Go To Changed File buttonGo To Changed File ⌃NClick this button to display all changed files in the current change set (and navigate to them). This button only appears when you are reviewing changes in multiple files (for example, in the Local Changes view .
the Edit button Jump to Source
Click this button to open the selected file in the active pane in the editor. The caret will be placed in the same position as in the Differences Viewer.
Viewer type

Use this list to choose a viewer type. The side-by-side viewer has two panels; the unified viewer has one panel only.

Both types of viewers enable you to

  • Edit code. Note that one can change text only in the right-hand part of the default viewer, or, in case of the unified viewer, in the lower ("after") line, that is in your local version of the file.

  • Perform the Apply/Append/Revert actions.


Use this list to define how the differences viewer should treat whitespaces.

  • Do not ignore: white spaces are important, and all differences are highlighted. This option is selected by default.

  • Trim whitespaces: ("\t", " ") , if they appear in the end and in the beginning of a line.

    • If two lines differ in trailing whitespaces only, these lines are considered equal.

    • If two lines are different, such trailing whitespaces are not highlighted in the By word mode.

  • Ignore whitespaces: white spaces are not important, regardless of their location in the source code.

  • Ignore whitespaces and empty lines: the following entities are ignored:

    • all whitespaces (as in the 'Ignore whitespaces' option)

    • all added or removed lines consisting of whitespaces only

    • all changes consisting of splitting or joining lines without changes to non-whitespace parts.
      For example, changing a b c to a \n b c is not highlighted in this mode.

Highlighting mode

Select the way differences granularity is highlighted.

The available options are:

  • Highlight words: the modified words are highlighted

  • Highlight lines: the modified lines are highlighted

  • Highlight split changes: if this option is selected, big changes are split into smaller 'atomic' changes.
    For example, A \n B vs. A X \n B X will be treated as two changes instead of one.

  • Highlight symbols: the modified symbols will be highlighted

  • Do not highlight: if this option is selected, the differences are not highlighted at all. This option is intended for significantly modified files, where highlighting only introduces additional difficulties.

the Collapse All buttonCollapse unchanged fragmentsClick this button to collapse all unchanged fragments in both files. The amount of non-collapsible unchanged lines is configurable in the Diff & Merge settings page.
the Synchronize buttonSynchronize scrollingClick this button to simultaneously scroll both differences panes; if this button is released, each of the panes can be scrolled independently.
the Settings buttonSettings

Click this button to invoke the list of available settings. Select or clear these options to show or hide whitespaces, line numbers and indent guides, to use or disable the use of soft wraps, and to set the highlighting level.

These commands are also available from the context menu of the differences viewer gutter.

Include into commit

This checkbox only appears if you invoke the Differences Viewer from the Commit Changes dialog with multiple changed files (all of which are deselected), and you explore the differences between them and hit the last difference in a file.

Select this checkbox if you want to include the file you've reviewed into the commit.

the Help buttonHelp
Click this button to show the corresponding help page.
⌃⇥Use this keyboard shortcut to switch between the panes of the Differences viewer. The active pane has the cursor.
apply left apply right

Use these chevron buttons to apply differences between panes (in case of the side-by-side viewer) or between lines (in case of the unified viewer).

The chevron buttons can change their behavior:

  • Click apply left and apply right to apply changes. This behavior is the default one.

  • Press Ctrl to change apply left or apply right to chevron button bottom right or chevron button bottom left and append changes.

Merge actions
compare options button N/A

Click this icon to invoke the list of options allowing you to compare different versions of a file to resolve a conflict.

Note that Base refers to the file version that the local and the repository versions originated from (initially displayed in the middle pane), while Middle refers to the resulting version.
the Apply Non-Conflicting Changes buttonApply All Non-Conflicting ChangesClick this button to apply all non-conflicting changes. You can also make this behavior automatic, by selecting the checkbox Automatically apply non-conflicting changes in the Diff & Merge page of the Settings/Preferences dialog.
Apply Non-Conflicting Changes from the Left/RightApply Non-Conflicting Changes from the Left/Right SideClick these buttons to merge non-conflicting changes from the left/right parts of the dialog.
N/A Annotate

This option is only available from the context menu of the gutter.

Use this option to explore who introduced which changes to the repository version of the file, and when. The annotations view lets you see detailed information for each line of code, such as the version from which this line originated, the ID of the user who committed this line, and the commit date.

For more details on annotations, refer to VCS annotations

Keyboard shortcuts

Keyboard shortcutDescription
Use this keyboard shortcut to show the popup menu of the most commonly used diff commands.
⌃⇥Use this keyboard shortcut to switch between the left and the right panes.
⌃⇧⇥Use this keyboard shortcut to select the position obtained by ⌃⇥ in the opposite pane.
⌃Z/⌃⇧ZUse this keyboard shortcut to undo/redo a merge operation. Conflicts will be kept in sync with the text.

Context menu commands

This context menu is available in the middle of the editor:

Show WhitespacesSelect this check command to show whitespaces as the dots in the Differences Viewer .
Show Line NumbersSelect this check command to show line numbers in the Differences Viewer.
Show Indent GuidesSelect this check command to have AppCode display vertical lines in the Differences Viewer to indicate positions of indents.
Use Soft WrapsSelect this check command to have AppCode wrap the lines of code, when the dialog is resized.
Highlighting levelUse this menu item to select the highlighting level in the Differences Viewer. To learn more about the level of highlighting, refer to the description of the Hector icon.
AnnotateSelect this check command to annotate the changes.

This context menu is available in both editors:

Accept/AppendSelect these commands to accept or append the lines shown in the Differences Viewer.
Compare with ClipboardSelect this command to compare the file in the respective pane of the Differences Viewer with the contents of the Clipboard .
AnnotateSelect this check command to annotate the changes.

This context menu is available in the right-hand strip of the Differences Viewer:

Go to high-priority problems only/Go to next problemClick one of these radio-buttons to define the way of navigating between the encountered problems.
Customize highlighting level Click to show the slider to change the highlighting level in the Differences Viewer.
Show code lens on scrollbar hover Enables viewing code outside of the visible area of the Differences Viewer when hovering the mouse over the scrollbar.
Last modified: 16 July 2020