How to enable Form features

Interactive form validation

1. Implement WebCore/page/ValidationMessageClient.h for your port
2. Set it to PageClients::validationMessageClient
3. Instantiate a Page object
4. page->settings()->setInteractiveFormValidationEnabled(true)

Doing step 3 and 4 without step 1 and 2 enables a platform-neutral form validation UI. But it has ​some unresolvable bugs. You should provide your ValidationMessageClient.

input[type=number]

If you have never done anything for input[type=number], it lacks the following features:

• Spin button UI
• Number localization

Spin button UI

This is optional. Opera has similar UI, but IE10 has no spin button. If you want the spin button UI, implement RenderTheme::adjustInnerSpinButtonStyle and paintInnerSpinButtonStyle.

Test: fast/forms/number/number-{appearance,spinbutton}*.html

Number localization

This is optional. IE10 localizes numbers, but Opera doesn't.

This feature requires Locale class implementation. If your port is using WebCore/platform/text/LocaleNone.cpp, this feature is disabled. Use WebCore/platform/text/{LocaleICU.cpp,mac/LocaleMac.mm,win/LocaleWin.cpp}, or implement your own Locale class.

Test: fast/forms/number/number-l10n-input.html

input[type=color]

Enable ENABLE_INPUT_TYPE_COLOR flag, and implement ChromeClient::createColorChooser.

Date, datetime-local, month, time, week input types

WebCore provides two UI types for them.

• Chooser-only UI (no ENABLE_INPUT_MULTIPLE_FIELDS_UI flag)

• Multiple-fields UI (ENABLE_INPUT_MULTIPLE_FIELDS_UI flag)

In the multiple-fields UI, users can specify values quickly with keyboard or mouse input. This UI is not suitable for mobile devices with touch input. Optionally we can provide platform-specific chooser dialog UI.

The Chooser-only UI is simple. We provide only platform-specific chooser dialog UI.

Chooser-only UI

1. Enable ENABLE_INPUT_TYPE_FOO without ENABLE_INPUT_MULTIPLE_FIELDS_UI
2. Implement Locale class (See "Number localization" section)
3. Implement ChromeClient::openDateTimeChooser

Multiple-fields UI

1. Enable ENABLE_INPUT_TYPE_FOO and ENABLE_INPUT_MULTIPLE_FIELDS_UI
2. Implement Locale class (See "Number localization" section)
3. Implement RenderTheme::adjustInnerSpinButonStyle and paintInnerSpinButtonStyle
4. Optionally, provide chooser dialog UI.
   1. Implement RenderTheme::supportsCalendarPicker so that it returns true for supported input types.
   2. Implement ChromeClient::openDateTimeChooser

ENABLE_CALENDAR_PICKER

WebCore has a calendar chooser implementation built with HTML. It supports date type, month type, week type, and year-month-day part of datetime-local type, and doesn't support time type and the time part of datetime-local type for now. So, the implementation is not enough for the chooser-only UI.

1. Enable ENABLE_PAGE_POPUP flag.
   This feature requires V8EnabledPerContext extended attribute. If your port uses JavaScriptCore, dont't use WebCore/page/DOMWindowPagePopup.idl and setup pagePopupController property in C++ code.
2. Implement ChromeClient::openPagePopup and closePagePopup.
3. Enable ENABLE_CALENDAR_PICKER flag
4. Update your build files so that it converts WebCore/Resources/pagepopups/{pickerCommon.js,pickerCommon.css,calendarPicker.js,calendarPicker.css} to C++ files by WebCore/make-file-arrays.py
5. Implement RenderTheme::supportsCalendarPicker so that it returns true for supported input types.
6. Implement ChromeClient::openDateTimeChooser. It should use ChromeClient::openPagePopup and the converted resources. See WebKit/chromium/src/DateTimeChooserImpl.cpp.

Figure: ENABLE_CALENDAR_PICKER

input[type=datetime]

Do not enable it. You can not make an appropriate UI with the current WebCore code.

Datalist element

This depends on input types.

Text field types

1. Enable ENABLE_DATALIST_ELEMENT
2. Implement RenderTheme::supportsDataListUI so that it returns true for supported types.
3. In WebKit layer, hook keyboard input, focus, or touch events for a target text field, and show UI to choose values of HTMLInputElement::dataList.

Range type

1. Enable ENABLE_DATALIST_ELEMENT
2. Implement RenderTheme::supportsDataListUI so that it returns true for range type.
3. Implement/override RenderTheme::slideTickSnappingThreshold, sliderTickSize, sliderTickOffsetFromTrackCenter.

Color type

1. Enable ENABLE_DATALIST_ELEMENT
2. Implement RenderTheme::supportsDataListUI so that it returns true for color type.
3. Your ColorChooser implementation should respect ColorChooserClient::shouldShowSuggestions and suggestions.

Date, datetime-local, month, time, week types

1. Enable ENABLE_DATALIST_ELEMENT
2. Implement RenderTheme::supportsDataListUI so that it returns true for supported types.
3. Implement ChromeClient::openDateTimeChooser so that it handles DateTimeChooserParameters::suggestionValues.