ThemeUtils.java
/*
* Copyright (C) 2015 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.appcompat.widget;
import static androidx.annotation.RestrictTo.Scope.LIBRARY;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.TypedArray;
import android.graphics.Color;
import android.util.TypedValue;
import android.view.View;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import androidx.appcompat.R;
import androidx.core.graphics.ColorUtils;
/**
* @hide
*/
@RestrictTo(LIBRARY)
public class ThemeUtils {
private static final String TAG = "ThemeUtils";
private static final ThreadLocal<TypedValue> TL_TYPED_VALUE = new ThreadLocal<>();
static final int[] DISABLED_STATE_SET = new int[]{-android.R.attr.state_enabled};
static final int[] FOCUSED_STATE_SET = new int[]{android.R.attr.state_focused};
static final int[] ACTIVATED_STATE_SET = new int[]{android.R.attr.state_activated};
static final int[] PRESSED_STATE_SET = new int[]{android.R.attr.state_pressed};
static final int[] CHECKED_STATE_SET = new int[]{android.R.attr.state_checked};
static final int[] SELECTED_STATE_SET = new int[]{android.R.attr.state_selected};
static final int[] NOT_PRESSED_OR_FOCUSED_STATE_SET = new int[]{
-android.R.attr.state_pressed, -android.R.attr.state_focused};
static final int[] EMPTY_STATE_SET = new int[0];
private static final int[] TEMP_ARRAY = new int[1];
/**
* Creates a color state list from the provided colors.
*
* @param textColor Regular text color.
* @param disabledTextColor Disabled text color.
* @return Color state list.
*/
@NonNull
public static ColorStateList createDisabledStateList(int textColor, int disabledTextColor) {
// Now create a new ColorStateList with the default color, and the new disabled
// color
final int[][] states = new int[2][];
final int[] colors = new int[2];
int i = 0;
// Disabled state
states[i] = DISABLED_STATE_SET;
colors[i] = disabledTextColor;
i++;
// Default state
states[i] = EMPTY_STATE_SET;
colors[i] = textColor;
i++;
return new ColorStateList(states, colors);
}
/**
* Resolves the color from the provided theme attribute.
*
* @param context Context. Must be non-null.
* @param attr Theme attribute for resolving color.
* @return Resolved color.
*/
public static int getThemeAttrColor(@NonNull Context context, int attr) {
TEMP_ARRAY[0] = attr;
TintTypedArray a = TintTypedArray.obtainStyledAttributes(context, null, TEMP_ARRAY);
try {
return a.getColor(0, 0);
} finally {
a.recycle();
}
}
/**
* Resolves the color state list from the provided theme attribute.
*
* @param context Context. Must be non-null.
* @param attr Theme attribute for resolving color state list.
* @return Resolved color state list.
*/
@Nullable
public static ColorStateList getThemeAttrColorStateList(@NonNull Context context, int attr) {
TEMP_ARRAY[0] = attr;
TintTypedArray a = TintTypedArray.obtainStyledAttributes(context, null, TEMP_ARRAY);
try {
return a.getColorStateList(0);
} finally {
a.recycle();
}
}
/**
* Resolves the disabled color from the provided theme attribute.
*
* @param context Context. Must be non-null.
* @param attr Theme attribute for resolving disabled color.
* @return Resolved disabled color.
*/
public static int getDisabledThemeAttrColor(@NonNull Context context, int attr) {
final ColorStateList csl = getThemeAttrColorStateList(context, attr);
if (csl != null && csl.isStateful()) {
// If the CSL is stateful, we'll assume it has a disabled state and use it
return csl.getColorForState(DISABLED_STATE_SET, csl.getDefaultColor());
} else {
// Else, we'll generate the color using disabledAlpha from the theme
final TypedValue tv = getTypedValue();
// Now retrieve the disabledAlpha value from the theme
context.getTheme().resolveAttribute(android.R.attr.disabledAlpha, tv, true);
final float disabledAlpha = tv.getFloat();
return getThemeAttrColor(context, attr, disabledAlpha);
}
}
private static TypedValue getTypedValue() {
TypedValue typedValue = TL_TYPED_VALUE.get();
if (typedValue == null) {
typedValue = new TypedValue();
TL_TYPED_VALUE.set(typedValue);
}
return typedValue;
}
static int getThemeAttrColor(@NonNull Context context, int attr, float alpha) {
final int color = getThemeAttrColor(context, attr);
final int originalAlpha = Color.alpha(color);
return ColorUtils.setAlphaComponent(color, Math.round(originalAlpha * alpha));
}
/**
* Checks that the specific view (which should be an AppCompat widget) is
* using a {@link Context} that is an AppCompat theme or its descendant.
*/
public static void checkAppCompatTheme(@NonNull View view, @NonNull Context context) {
TypedArray a = context.obtainStyledAttributes(R.styleable.AppCompatTheme);
try {
// Same check as in AppCompatDelegateImpl - do not allow using AppCompat widgets
// without a top-level AppCompat theme (or its descendant). For now flag this as
// an error-level log message.
if (!a.hasValue(R.styleable.AppCompatTheme_windowActionBar)) {
android.util.Log.e(TAG, "View " + view.getClass()
+ " is an AppCompat widget that can only be used with a "
+ "Theme.AppCompat theme (or descendant).");
}
} finally {
a.recycle();
}
}
private ThemeUtils() {
}
}