React Native Modal Dropdown Versions Save

• Fix #139 renderButtonText renders [object Object] if there is a call to setState in onSelect or renderButtonText functions

• Fix #127 renderButtonText does not work on select(idx) (Thanks to @swb2016)
• Code optimization.

v0.6.0

• Introduce renderButtonText property to extract button text from object array data.

• React 16 compatibility.
• Fix #84

v0.4.4

• Expose keyboardShouldPersistTaps prop on dropdown (ListView).

v0.4.3

• Add ability to style dropdown text. See dropdownTextStyle and dropdownTextHighlightStyle. Thanks to @evansiroky
• Fix TouchableWithNativeFeedback should be TouchableNativeFeedback

• Add animated option. #44
• Add showsVerticalScrollIndicator option
• Add landscape orientation support. #45

• Fix bug: #27 Fix a flex style bug.
• Enhancement: #26 Support object type of options.

• New feature: Add adjustFrame prop for user to adjust the frame style of the dropdown in case the component calculate a mistake frame. (refer to #5) (code sample)
• Enhancement: #16 Prevent from warnings if array of styles is used instead of stylesheet or object. Thanks to @NikolaBorislavovHristov .

• Enhancement: Compatible with react-native v0.36.0 which has a break change causes the default button with zero size.