xref: /wear/protolayout/protolayout-material/src/main/java/androidx/wear/protolayout/material/Typography.java

/*
 * Copyright 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package androidx.wear.protolayout.material;

import static android.os.Build.VERSION.SDK_INT;
import static android.os.Build.VERSION_CODES.UPSIDE_DOWN_CAKE;

import static androidx.annotation.Dimension.DP;
import static androidx.annotation.Dimension.SP;
import static androidx.wear.protolayout.DimensionBuilders.sp;
import static androidx.wear.protolayout.LayoutElementBuilders.FONT_VARIANT_BODY;
import static androidx.wear.protolayout.LayoutElementBuilders.FONT_VARIANT_TITLE;
import static androidx.wear.protolayout.LayoutElementBuilders.FONT_WEIGHT_BOLD;
import static androidx.wear.protolayout.LayoutElementBuilders.FONT_WEIGHT_MEDIUM;
import static androidx.wear.protolayout.LayoutElementBuilders.FONT_WEIGHT_NORMAL;
import static androidx.wear.protolayout.materialcore.Helper.checkNotNull;

import android.annotation.SuppressLint;
import android.content.Context;

import androidx.annotation.Dimension;
import androidx.annotation.IntDef;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import androidx.wear.protolayout.DimensionBuilders;
import androidx.wear.protolayout.DimensionBuilders.SpProp;
import androidx.wear.protolayout.LayoutElementBuilders.FontStyle;
import androidx.wear.protolayout.LayoutElementBuilders.FontVariant;
import androidx.wear.protolayout.LayoutElementBuilders.FontWeight;
import androidx.wear.protolayout.materialcore.fontscaling.FontScaleConverter;
import androidx.wear.protolayout.materialcore.fontscaling.FontScaleConverterFactory;

import org.jspecify.annotations.NonNull;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.HashMap;
import java.util.Map;

/** Typography styles, currently set up to match Wear's styling. */
public class Typography {
    /** Typography for large display text. */
    public static final int TYPOGRAPHY_DISPLAY1 = 1;

    /** Typography for medium display text. */
    public static final int TYPOGRAPHY_DISPLAY2 = 2;

    /** Typography for small display text. */
    public static final int TYPOGRAPHY_DISPLAY3 = 3;

    /** Typography for large title text. */
    public static final int TYPOGRAPHY_TITLE1 = 4;

    /** Typography for medium title text. */
    public static final int TYPOGRAPHY_TITLE2 = 5;

    /** Typography for small title text. */
    public static final int TYPOGRAPHY_TITLE3 = 6;

    /** Typography for large body text. */
    public static final int TYPOGRAPHY_BODY1 = 7;

    /** Typography for medium body text. */
    public static final int TYPOGRAPHY_BODY2 = 8;

    /** Typography for bold button text. */
    public static final int TYPOGRAPHY_BUTTON = 9;

    /** Typography for large caption text. */
    public static final int TYPOGRAPHY_CAPTION1 = 10;

    /** Typography for medium caption text. */
    public static final int TYPOGRAPHY_CAPTION2 = 11;

    /** Typography for small caption text. */
    public static final int TYPOGRAPHY_CAPTION3 = 12;

    @RestrictTo(Scope.LIBRARY)
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({
        TYPOGRAPHY_DISPLAY1,
        TYPOGRAPHY_DISPLAY2,
        TYPOGRAPHY_DISPLAY3,
        TYPOGRAPHY_TITLE1,
        TYPOGRAPHY_TITLE2,
        TYPOGRAPHY_TITLE3,
        TYPOGRAPHY_BODY1,
        TYPOGRAPHY_BODY2,
        TYPOGRAPHY_BUTTON,
        TYPOGRAPHY_CAPTION1,
        TYPOGRAPHY_CAPTION2,
        TYPOGRAPHY_CAPTION3
    })
    @interface TypographyName {}

    /** Mapping for line height for different typography. */
    private static final @NonNull Map<Integer, Float> TYPOGRAPHY_TO_LINE_HEIGHT_SP =
            new HashMap<>();

    static {
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_DISPLAY1, 46f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_DISPLAY2, 40f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_DISPLAY3, 36f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_TITLE1, 28f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_TITLE2, 24f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_TITLE3, 20f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_BODY1, 20f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_BODY2, 18f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_BUTTON, 19f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_CAPTION1, 18f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_CAPTION2, 16f);
        TYPOGRAPHY_TO_LINE_HEIGHT_SP.put(TYPOGRAPHY_CAPTION3, 14f);
    }

    private Typography() {}

    /**
     * Returns the {@link FontStyle.Builder} for the given FontStyle code with the recommended size,
     * weight and letter spacing. Font will be scalable.
     */
    static FontStyle.@NonNull Builder getFontStyleBuilder(
            @TypographyName int fontStyleCode, @NonNull Context context) {
        return getFontStyleBuilder(fontStyleCode, context, true);
    }

    /**
     * Returns the {@link FontStyle.Builder} for the given Typography code with the recommended
     * size, weight and letter spacing, with the option to make this font not scalable.
     */
    static FontStyle.@NonNull Builder getFontStyleBuilder(
            @TypographyName int typographyCode, @NonNull Context context, boolean isScalable) {
        switch (typographyCode) {
            case TYPOGRAPHY_BODY1:
                return body1(isScalable, context);
            case TYPOGRAPHY_BODY2:
                return body2(isScalable, context);
            case TYPOGRAPHY_BUTTON:
                return button(isScalable, context);
            case TYPOGRAPHY_CAPTION1:
                return caption1(isScalable, context);
            case TYPOGRAPHY_CAPTION2:
                return caption2(isScalable, context);
            case TYPOGRAPHY_CAPTION3:
                return caption3(isScalable, context);
            case TYPOGRAPHY_DISPLAY1:
                return display1(isScalable, context);
            case TYPOGRAPHY_DISPLAY2:
                return display2(isScalable, context);
            case TYPOGRAPHY_DISPLAY3:
                return display3(isScalable, context);
            case TYPOGRAPHY_TITLE1:
                return title1(isScalable, context);
            case TYPOGRAPHY_TITLE2:
                return title2(isScalable, context);
            case TYPOGRAPHY_TITLE3:
                return title3(isScalable, context);
            default:
                // Shouldn't happen.
                throw new IllegalArgumentException(
                        "Typography " + typographyCode + " doesn't exist.");
        }
    }

    /**
     * Returns the recommended line height for the given Typography to be added to the Text
     * component.
     */
    static @NonNull SpProp getLineHeightForTypography(@TypographyName int typography) {
        if (!TYPOGRAPHY_TO_LINE_HEIGHT_SP.containsKey(typography)) {
            throw new IllegalArgumentException("Typography " + typography + " doesn't exist.");
        }
        return sp(checkNotNull(TYPOGRAPHY_TO_LINE_HEIGHT_SP.get(typography)).intValue());
    }

    /**
     * This is a helper function to make the font not scalable. It should interpret in value as DP
     * and convert it to SP which is needed to be passed in as a font size. However, we will pass an
     * SP object to it, because the default style is defined in it, but for the case when the font
     * size on device is 1, so the DP is equal to SP.
     */
    @Dimension(unit = SP)
    private static float dpToSp(float fontScale, @Dimension(unit = DP) float valueDp) {
        FontScaleConverter converter =
                (SDK_INT >= UPSIDE_DOWN_CAKE)
                        ? FontScaleConverterFactory.forScale(fontScale)
                        : null;

        if (converter == null) {
            return dpToSpLinear(fontScale, valueDp);
        }

        return converter.convertDpToSp(valueDp);
    }

    @Dimension(unit = SP)
    private static float dpToSpLinear(float fontScale, @Dimension(unit = DP) float valueDp) {
        return valueDp / fontScale;
    }

    // The @Dimension(unit = SP) on sp() is seemingly being ignored, so lint complains that we're
    // passing SP to something expecting PX. Just suppress the warning for now.
    @SuppressLint("ResourceType")
    private static FontStyle.Builder createFontStyleBuilder(
            @Dimension(unit = SP) int size,
            @FontWeight int weight,
            @FontVariant int variant,
            float letterSpacing,
            boolean isScalable,
            @NonNull Context context) {
        float fontScale = context.getResources().getConfiguration().fontScale;
        return new FontStyle.Builder()
                .setSize(DimensionBuilders.sp(isScalable ? size : dpToSp(fontScale, size)))
                .setLetterSpacing(DimensionBuilders.em(letterSpacing))
                .setVariant(variant)
                .setWeight(weight);
    }

    /** Font style for large display text. */
    private static FontStyle.@NonNull Builder display1(boolean isScalable,
            @NonNull Context context) {
        return createFontStyleBuilder(
                40, FONT_WEIGHT_MEDIUM, FONT_VARIANT_TITLE, 0.01f, isScalable, context);
    }

    /** Font style for medium display text. */
    private static FontStyle.@NonNull Builder display2(boolean isScalable,
            @NonNull Context context) {
        return createFontStyleBuilder(
                34, FONT_WEIGHT_MEDIUM, FONT_VARIANT_TITLE, 0.03f, isScalable, context);
    }

    /** Font style for small display text. */
    private static FontStyle.@NonNull Builder display3(boolean isScalable,
            @NonNull Context context) {
        return createFontStyleBuilder(
                30, FONT_WEIGHT_MEDIUM, FONT_VARIANT_TITLE, 0.03f, isScalable, context);
    }

    /** Font style for large title text. */
    private static FontStyle.@NonNull Builder title1(boolean isScalable, @NonNull Context context) {
        return createFontStyleBuilder(
                24, FONT_WEIGHT_MEDIUM, FONT_VARIANT_TITLE, 0.008f, isScalable, context);
    }

    /** Font style for medium title text. */
    private static FontStyle.@NonNull Builder title2(boolean isScalable, @NonNull Context context) {
        return createFontStyleBuilder(
                20, FONT_WEIGHT_MEDIUM, FONT_VARIANT_TITLE, 0.01f, isScalable, context);
    }

    /** Font style for small title text. */
    private static FontStyle.@NonNull Builder title3(boolean isScalable, @NonNull Context context) {
        return createFontStyleBuilder(
                16, FONT_WEIGHT_MEDIUM, FONT_VARIANT_TITLE, 0.01f, isScalable, context);
    }

    /** Font style for normal body text. */
    private static FontStyle.@NonNull Builder body1(boolean isScalable, @NonNull Context context) {
        return createFontStyleBuilder(
                16, FONT_WEIGHT_NORMAL, FONT_VARIANT_BODY, 0.01f, isScalable, context);
    }

    /** Font style for small body text. */
    private static FontStyle.@NonNull Builder body2(boolean isScalable, @NonNull Context context) {
        return createFontStyleBuilder(
                14, FONT_WEIGHT_NORMAL, FONT_VARIANT_BODY, 0.014f, isScalable, context);
    }

    /** Font style for bold button text. */
    private static FontStyle.@NonNull Builder button(boolean isScalable, @NonNull Context context) {
        return createFontStyleBuilder(
                15, FONT_WEIGHT_BOLD, FONT_VARIANT_BODY, 0.03f, isScalable, context);
    }

    /** Font style for large caption text. */
    private static FontStyle.@NonNull Builder caption1(boolean isScalable,
            @NonNull Context context) {
        return createFontStyleBuilder(
                14, FONT_WEIGHT_MEDIUM, FONT_VARIANT_BODY, 0.01f, isScalable, context);
    }

    /** Font style for medium caption text. */
    private static FontStyle.@NonNull Builder caption2(boolean isScalable,
            @NonNull Context context) {
        return createFontStyleBuilder(
                12, FONT_WEIGHT_MEDIUM, FONT_VARIANT_BODY, 0.01f, isScalable, context);
    }

    /** Font style for small caption text. */
    private static FontStyle.@NonNull Builder caption3(boolean isScalable,
            @NonNull Context context) {
        return createFontStyleBuilder(
                10, FONT_WEIGHT_MEDIUM, FONT_VARIANT_BODY, 0.01f, isScalable, context);
    }
}