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Commit 1e6256e8 authored by Tyler Freeman's avatar Tyler Freeman Committed by Automerger Merge Worker
Browse files

feat(non linear font scaling): add... 

feat(non linear font scaling): add FontScaleConverterFactory.isNonLinearFontScalingActive() am: da945139 am: ae84a33a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22537770



Change-Id: If31cbfbbfdcfcc6bd9bb8849a0d073cfc6d27a08
Signed-off-by: default avatarAutomerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
parents 42a82a15 ae84a33a

core/java/android/content/res/FontScaleConverterFactory.java

+22 −4
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ public class FontScaleConverterFactory { 
    @VisibleForTesting

    static final SparseArray<FontScaleConverter> LOOKUP_TABLES = new SparseArray<>();



    private static float sMinScaleBeforeCurvesApplied = 1.05f;



    static {

        // These were generated by frameworks/base/tools/fonts/font-scaling-array-generator.js and

        // manually tweaked for optimum readability.
@@ -82,10 +84,29 @@ public class FontScaleConverterFactory { 
                        new float[] {  16f,   20f,   24f,   26f,   30f,   34f,   36f,   38f,  100})

        );



        sMinScaleBeforeCurvesApplied = getScaleFromKey(LOOKUP_TABLES.keyAt(0)) - 0.02f;

        if (sMinScaleBeforeCurvesApplied <= 1.0f) {

            throw new IllegalStateException(

                    "You should only apply non-linear scaling to font scales > 1"

            );

        }

    }



    private FontScaleConverterFactory() {}



    /**

     * Returns true if non-linear font scaling curves would be in effect for the given scale, false

     * if the scaling would follow a linear curve or for no scaling.

     *

     * <p>Example usage:

     * <code>isNonLinearFontScalingActive(getResources().getConfiguration().fontScale)</code>

     *

     * @hide

     */

    public static boolean isNonLinearFontScalingActive(float fontScale) {

        return fontScale >= sMinScaleBeforeCurvesApplied;

    }



    /**

     * Finds a matching FontScaleConverter for the given fontScale factor.

     *
@@ -97,10 +118,7 @@ public class FontScaleConverterFactory { 
     */

    @Nullable

    public static FontScaleConverter forScale(float fontScale) {

        if (fontScale <= 1) {

            // We don't need non-linear curves for shrinking text or for 100%.

            // Also, fontScale==0 should not have a curve either.

            // And ignore negative font scales; that's just silly.

        if (!isNonLinearFontScalingActive(fontScale)) {

            return null;

        }

core/tests/coretests/src/android/content/res/FontScaleConverterFactoryTest.kt

+16 −0
Original line number Diff line number Diff line
@@ -122,6 +122,22 @@ class FontScaleConverterFactoryTest { 
        }

    }



    @SmallTest

    fun testIsNonLinearFontScalingActive() {

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(1f)).isFalse()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(0f)).isFalse()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(-1f)).isFalse()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(0.85f)).isFalse()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(1.02f)).isFalse()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(1.10f)).isFalse()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(1.15f)).isTrue()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(1.1499999f))

                .isTrue()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(1.5f)).isTrue()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(2f)).isTrue()

        assertThat(FontScaleConverterFactory.isNonLinearFontScalingActive(3f)).isTrue()

    }



    @LargeTest

    @Test

    fun allFeasibleScalesAndConversionsDoNotCrash() {