Make color transparent (Hex values of Alpha color codes)

Here's a correct table of percentages to hex values. E.g. for 50% white you'd use #80FFFFFF

Using the below values one can achieve transparency in any color.

AARRGGBB where AA represents the alpha value and can be replaced with hex values from below table to achieve desired transparency.

• 100% — FF
• 95% — F2
• 90% — E6
• 85% — D9
• 80% — CC
• 75% — BF
• 70% — B3
• 65% — A6
• 60% — 99
• 55% — 8C
• 50% — 80
• 45% — 73
• 40% — 66
• 35% — 59
• 30% — 4D
• 25% — 40
• 20% — 33
• 15% — 26
• 10% — 1A
• 5% — 0D
• 0% — 00

Taken from SO for my future reference 

http://stackoverflow.com/questions/5445085/understanding-colors-in-android-6-characters/11019879#11019879 

Screen resolutions

• 36x36 (0.75x) for low-density
• 48x48 (1.0x baseline) for medium-density
• 72x72 (1.5x) for high-density
• 96x96 (2.0x) for extra-high-density
• 144x144 (3.0x) for extra-extra-high-density
• 192x192 (4.0x) for extra-extra-extra-high-density (launcher icon only; see note above)

In short 

mdpi

ldpi = 0.75 X mdpi

hdpi = 1.5 X mdpi

xhdpi = 2 X mdpi

xxhdpi = 3 X mdpi

xxxhdpi = 4 X mdpi

Android Studio important points

1. To Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
            File --> Other Settings --> Default settings --> Build, Execution, Deployment --> Compiler

            Command-line option takes -stacktrace option to get the stack trace.
            Run with --info or --debug option to get more log output.

2. Suggestion: add 'tools:replace="android:icon"' to <application> element in AndroidManifestAdd xmlns:tools="http://schemas.android.com/tools" to manifest tag and tools:replace="android:icon,android:theme,android:label" to application tag.

3. For the error unmappable character for encoding UTF-8.......... Add the following line to build.gradle
android {
 ...
compileOptions.encoding = 'ISO-8859-1'
 }

4. Add support library to Android Studio project

5. Open File -> Project Structure... menu.
6. Select Modules in the left pane, choose your project's main module in the middle pane and openDependencies tab in the right pane.
7. Click the plus sign in the right panel and select "Maven dependency" from the list. A Maven dependency dialog will pop up.
8. Enter "support-v4" into the search field and click the icon with magnifying glass.
9. Run the below command in terminal to detect which image file is causing the merge to fail. After running the command check for buildLog.txt file in Project window, search for Error which will point to the exact file causing the issue.
gradlew :app:mergeDebugResources --debug > buildLog.txt
10. All com.android.support libraries must use the exact same version specification
Solution : https://stackoverflow.com/a/42374426 

Compiling POCO libraries for Android

Create a standard toolchain

http://developer.android.com/ndk/guides/standalone_toolchain.html


$NDK_ROOT/build/tools/make-standalone-toolchain.sh \
--arch=arm --platform=android-18 --toolchain=arm-linux-androideabi-4.8 --install-dir=/Users/saba/azhar/work/android/POCO/poco-android-toolchain

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On El-Captain Install the openssl (openssl should be already present on a linux system)

brew install openssl
brew link openssl --force


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POCO build complete edition with NetSSL_OpenSSL and Crypto(without ODBC and MySQL)

cd /Users/ss/aa/work/android/POCO/poco-1.6.1-all_Shared

export PATH=$PATH:/Users/ss/aa/work/android/POCO/poco-android-toolchain/bin

./configure --config=Android --no-samples --no-tests --omit=Data/ODBC,Data/MySQL --include-path=/usr/local/Cellar/openssl/1.0.2d_1/include --library-path=/usr/local/Cellar/openssl/1.0.2d_1/lib

make -s -j4
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POCO build basic edition 

cd /Users/ss/aa/work/android/poco-1.6.1

export PATH=$PATH:/Users/ss/aa/work/android/POCO/poco-android-toolchain/bin

./configure --config=Android --no-samples --no-tests

make -s -j4

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By default POCO will compile static libs (.a) files but yet I haven't been able to successfully create a JNI wrapper to use functions available in static libs. So I compiled the shared libs and used them.

To generate shared libs open the below make file
/Users/ss/aa/work/android/POCO/poco-1.6.1-all_Shared/build/config/Android 

and change from

LINKMODE           ?= STATIC

to

LINKMODE           ?= SHARED

After the complete POCO libs are built they should be available in lib folder present under Root of POCO  (poco-1.6.1-all_Shared and poco-1.6.1 in my case)

Although I could generate all static libs, I could not generate the libPocoNetSSL.so lib.
I guess it was because the openssl lib that the POCO code referes to was using a static lib on MAC and creating a shared lib using static lib was causing some problem.

I speculate that the problem should not exist on a linux machine. Will try out soon and post the results.

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Do a clean up of POCO

make clean
rm -f -R lib
popd

rm -f -R Platform/Android/lib

rm -f -R Platform/iOS/lib

rm -f -R Platform/MacOS/lib

rm -f -R Build/iOS

rm -f -R Build/Android

rm -f -R Build/Darwin

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System 

OS X El Capitan
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Reference : -

http://pocoproject.org/docs/99300-AndroidPlatformNotes.html