chrome: Add ability to block/handle chrome commands (menus & keyboard shortcuts)

[magreenblatt]

Original report by me.

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Some applications won’t want default handling of Chrome keyboard shortcuts.

[magreenblatt]

See issue #2969 for background on the Chrome runtime.

[magreenblatt]

Most commands are routed through BrowserCommandController::ExecuteCommandWithDisposition with IDs defined in chrome_command_ids.h.

Keyboard shortcuts are delivered to this method via call stacks like (at M100 on Windows):

>   libcef.dll!chrome::BrowserCommandController::ExecuteCommandWithDisposition(int id, WindowOpenDisposition disposition, base::TimeTicks time_stamp) Line 374  C++
    libcef.dll!chrome::BrowserCommandController::ExecuteCommand(int id, base::TimeTicks time_stamp) Line 361    C++
    libcef.dll!chrome::ExecuteCommand(Browser * browser, int command, base::TimeTicks time_stamp) Line 413  C++
    libcef.dll!BrowserView::AcceleratorPressed(const ui::Accelerator & accelerator) Line 3551   C++
    ui_base.dll!ui::AcceleratorManager::AcceleratorTargetInfo::TryProcess(const ui::Accelerator & accelerator) Line 152 C++
    ui_base.dll!ui::AcceleratorManager::Process(const ui::Accelerator & accelerator) Line 83    C++
    views.dll!views::FocusManager::ProcessAccelerator(const ui::Accelerator & accelerator) Line 536 C++
    views.dll!views::FocusManager::OnKeyEvent(const ui::KeyEvent & event) Line 113  C++
    views.dll!views::FocusManagerEventHandler::OnKeyEvent(ui::KeyEvent * event) Line 25 C++
    events.dll!ui::EventHandler::OnEvent(ui::Event * event) Line 32 C++

The translation of accelerator to command ID is performed by BrowserView::FindCommandIdForAccelerator using the mapping from accelerator_table.cc.

‌

[magreenblatt]

We should probably include the contents of chrome_command_ids.h in the CEF binary distribution, and allow the client to block/handle any command via a callback from ExecuteCommandWithDisposition.

[magreenblatt]

• changed title from "chrome: Add ability to disable/override default keyboard shortcut handling" to "chrome: Add ability to handle/disable chrome commands (menus & keyboard shortcuts)"

[magreenblatt]

For this issue we’ll limit functionality to blocking or handling commands that are otherwise enabled. Overriding the current enable/disable state (in a menu, for example) will be left for another time/issue. That would likely require changing the registrations in BrowserCommandController::InitCommandState and possibly other places.

[magreenblatt]

• changed title from "chrome: Add ability to handle/disable chrome commands (menus & keyboard shortcuts)" to "chrome: Add ability to block/handle chrome commands (menus & keyboard shortcuts)"

[magreenblatt]

chrome: Add ability to handle chrome menu/keyboard commands (fixes issue #3280)

This change adds a CefCommandHandler::OnChromeCommand callback for optionally
handling Chrome commands triggered via menus or keyboard shortcuts. Supported
command IDs are listed in a new cef_command_ids.h header file.

To test: Run cefclient --enable-chrome-runtime --hide-controls. Most commands
will blocked and removed from context menus.

→ <<cset 2f5838eaaaee (bb)>>

[magreenblatt]

• changed state from "new" to "resolved"

[magreenblatt]

Adding additional support for customizing the Chrome toolbar contents.

The above highlighted toolbar zones are controlled as follows:

• Page action icon = PageActionIconController::Init
• Toolbar button = ToolbarView::Init
• App menu contents = AppMenu::Init

Visibility of the back, forward, reload, site information, experiments, media controls, extensions, profile and app menu toolbar buttons will not be configurable at this time (each hidden button will require custom code in ToolbarView, and verification that the app doesn’t crash as a result). Return CEF_CTT_LOCATION via CefBrowserViewDelegate::GetChromeToolbarType if you don't want any of that functionality.

‌

[magreenblatt]

chrome: Add ability to hide toolbar and app menu contents (see issue #3280)

This change adds new CefCommandHandler callbacks for optionally hiding
specific Chrome toolbar icons, buttons and app menu items.

To test: Run cefclient --enable-chrome-runtime --filter-chrome-commands.
Most icons, buttons and app/context menu items will be hidden.

→ <<cset 14dd0c0d0616 (bb)>>

[magreenblatt]

chrome: Add ability to hide toolbar and app menu contents (see issue #3280)

This change adds new CefCommandHandler callbacks for optionally hiding
specific Chrome toolbar icons, buttons and app menu items.

To test: Run cefclient --enable-chrome-runtime --filter-chrome-commands.
Most icons, buttons and app/context menu items will be hidden.

→ <<cset f8b9812cb40d (bb)>>