Collapse/expand all code blocks

`Ctrl` + `↑ Shift` + `+`

All hotkeys for Android Studio

General Save all	`Ctrl` + `S`
General Synchronize	`Ctrl` + `Alt` + `Y`
General Maximize/minimize editor	`Ctrl` + `↑ Shift` + `F12`
General Add to favorites	`Alt` + `↑ Shift` + `F`
General Inspect current file with current profile	`Alt` + `↑ Shift` + `I`
General (backquote) Quick switch scheme	`Ctrl` + `
General Open settings dialogue	`Ctrl` + `Alt` + `S`
General Open project structure dialog	`Ctrl` + `Alt` + `↑ Shift` + `S`
General Switch between tabs and tool window	`Ctrl` + `⭾ Tab`
Navigating and searching Find	`Ctrl` + `F`
Navigating and searching Find next	`F3`
Navigating and searching Find previous	`↑ Shift` + `F3`
Navigating and searching Replace	`Ctrl` + `R`
Navigating and searching Find action	`Ctrl` + `↑ Shift` + `A`
Navigating and searching Search by symbol name	`Ctrl` + `Alt` + `↑ Shift` + `N`
Navigating and searching Find class	`Ctrl` + `N`
Navigating and searching Find file (instead of class)	`Ctrl` + `↑ Shift` + `N`
Navigating and searching Find in path	`Ctrl` + `↑ Shift` + `F`
Navigating and searching Open file structure pop-up	`Ctrl` + `F12`
Navigating and searching Navigate between open editor tabs	`Alt` + `← →`
Navigating and searching Jump to source	`F4`
Writing code Smart line split	`Ctrl` + `⤶ Enter`
Navigating and searching Open current editor tab in new window	`↑ Shift` + `F4`
Navigating and searching Recently opened files pop-up	`Ctrl` + `E`
Navigating and searching Recently edited files pop-up	`Ctrl` + `↑ Shift` + `E`
Navigating and searching Go to last edit location	`Ctrl` + `↑ Shift` + `⬅ Backspace`
Navigating and searching Close active editor tab	`Ctrl` + `F4`
Navigating and searching Return to editor window from a tool window	`Esc`
Navigating and searching Hide active or last active tool window	`↑ Shift` + `Esc`
Navigating and searching Go to line	`Ctrl` + `G`
Navigating and searching Open type hierarchy	`Ctrl` + `H`
Navigating and searching Open method hierarchy	`Ctrl` + `↑ Shift` + `H`
Navigating and searching Open call hierarchy	`Ctrl` + `Alt` + `H`
Writing code Generate code (getters, setters, constructors, hashCode/equals, toString, new file, new class)	`Alt` + `Insert`
Writing code Override methods	`Ctrl` + `O`
Writing code Implement methods	`Ctrl` + `I`
Writing code Surround with (if...else / try...catch / etc.)	`Ctrl` + `Alt` + `T`
Writing code Delete line at caret	`Ctrl` + `Y`
Writing code Collapse/expand current code block	`Ctrl` + `-`
Writing code Collapse/expand current code block	`Ctrl` + `+`
Writing code Collapse/expand all code blocks	`Ctrl` + `↑ Shift` + `-`
Writing code Collapse/expand all code blocks	`Ctrl` + `↑ Shift` + `+`
Writing code Duplicate current line or selection	`Ctrl` + `D`
Writing code Basic code completion	`Ctrl` + `Space`
Writing code Smart code completion (filters the list of methods and variables by expected type)	`Ctrl` + `↑ Shift` + `Space`
Writing code Complete statement	`Ctrl` + `↑ Shift` + `⤶ Enter`
Writing code Quick documentation lookup	`Ctrl` + `Q`
Writing code Show parameters for selected method	`Ctrl` + `P`
Writing code Go to declaration (directly)	`Ctrl` + `B`
Writing code Go to declaration (directly)	`Ctrl` + `Mouse left click`
Writing code Go to implementations	`Ctrl` + `Alt` + `B`
Writing code Go to super-method/super-class	`Ctrl` + `U`
Writing code Open quick definition lookup	`Ctrl` + `↑ Shift` + `I`
Writing code Toggle project tool window visibility	`Alt` + `1`
Writing code Toggle bookmark	`F11`
Writing code Toggle bookmark with mnemonic	`Ctrl` + `F11`
Writing code Comment/uncomment with line comment	`Ctrl` + `/`
Writing code Comment/uncomment with block comment	`Ctrl` + `↑ Shift` + `/`
Writing code Select successively increasing code blocks	`Ctrl` + `W`
Writing code Move to code block start	`Ctrl` + `[`
Writing code Move to code block end	`Ctrl` + `]`
Writing code Select to the code block start	`Ctrl` + `↑ Shift` + `[`
Writing code Select to the code block end	`Ctrl` + `↑ Shift` + `]`
Writing code Delete to end of word	`Ctrl` + `Del`
Writing code Delete to start of word	`Ctrl` + `⬅ Backspace`
Writing code Optimize imports	`Ctrl` + `Alt` + `O`
Writing code Project quick fix (show intention actions and quick fixes)	`Alt` + `⤶ Enter`
Writing code Reformat code	`Ctrl` + `Alt` + `L`
Writing code Auto-indent lines	`Ctrl` + `Alt` + `I`
Writing code Indent/unindent lines	`⭾ Tab`
Writing code Indent/unindent lines	`↑ Shift` + `⭾ Tab`
Writing code Smart line join	`Ctrl` + `↑ Shift` + `J`
Writing code Start new line	`↑ Shift` + `⤶ Enter`
Writing code Next/previous highlighted error	`F2`
Writing code Next/previous highlighted error	`↑ Shift` + `F2`
Build and run Build	`Ctrl` + `F9`
Build and run Build and run	`↑ Shift` + `F10`
Build and run Apply changes	`Ctrl` + `F10`
Debugging Debug	`↑ Shift` + `F9`
Debugging Step over	`F8`
Debugging Step into	`F7`
Debugging Smart step into	`↑ Shift` + `F7`
Debugging Step out	`↑ Shift` + `F8`
Debugging Run to cursor	`Alt` + `F9`
Debugging Evaluate expression	`Alt` + `F8`
Debugging Resume program	`F9`
Debugging Toggle breakpoint	`Ctrl` + `F8`
Debugging View breakpoints	`Ctrl` + `↑ Shift` + `F8`
Refactoring Copy	`F5`
Refactoring Move	`F6`
Refactoring Safe delete	`Alt` + `Del`
Refactoring Rename	`↑ Shift` + `F6`
Refactoring Change signature	`Ctrl` + `F6`
Refactoring Inline	`Ctrl` + `Alt` + `N`
Refactoring Extract method	`Ctrl` + `Alt` + `M`
Refactoring Extract variable	`Ctrl` + `Alt` + `V`
Refactoring Extract field	`Ctrl` + `Alt` + `F`
Refactoring Extract constant	`Ctrl` + `Alt` + `C`
Refactoring Extract parameter	`Ctrl` + `Alt` + `P`
Version Control / Local History Commit project to VCS	`Ctrl` + `K`
Version Control / Local History Update project from VCS	`Ctrl` + `T`
Version Control / Local History View recent changes	`Alt` + `↑ Shift` + `C`
Version Control / Local History (backquote) Open VCS popup	`Alt` + `