在Android中为汉堡包导航菜单图标添加徽章计数器

Question

我的问题与这个问题相同(这不是这个问题的重复).

这个问题的唯一答案对我不起作用,而不是将活动标题左侧的默认汉堡包图标更改,它只是在我的活动标题右侧添加了一个额外的汉堡包图标.

那么我该怎么做呢:

我一整天都在四处寻找,但却无处可去.

我看到Toolbar有一种setNavigationIcon(Drawable drawable)方法.理想情况下,我想使用layout(包含汉堡包图标和徽章视图)而不是a Drawable,但我不确定这是否可以实现 - 或者是否有更好的方法？

注意 - 这不是关于如何创建徽章视图的问题.我已经创建了它并在导航菜单项本身上实现了它.所以我现在只需要在默认的汉堡包图标上添加类似的徽章视图.

Answer 1

从支持库的24.2.0版本开始,v7版本ActionBarDrawerToggle提供了该setDrawerArrowDrawable()方法作为自定义切换图标的方法.DrawerArrowDrawable是提供该默认图标的类,可以根据需要对其进行子类化以更改它.

例如,BadgeDrawerArrowDrawable该类重写了draw()在超类自绘之后添加基本红色和白色徽章的方法.这允许汉堡包箭头动画保留在下面.

import android.content.Context;
import android.graphics.Color;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.support.v7.graphics.drawable.DrawerArrowDrawable;
import java.util.Objects;

public class BadgeDrawerArrowDrawable extends DrawerArrowDrawable {

    // Fraction of the drawable's intrinsic size we want the badge to be.
    private static final float SIZE_FACTOR = .3f;
    private static final float HALF_SIZE_FACTOR = SIZE_FACTOR / 2;

    private Paint backgroundPaint;
    private Paint textPaint;
    private String text;
    private boolean enabled = true;

    public BadgeDrawerArrowDrawable(Context context) {
        super(context);

        backgroundPaint = new Paint();
        backgroundPaint.setColor(Color.RED);
        backgroundPaint.setAntiAlias(true);

        textPaint = new Paint();
        textPaint.setColor(Color.WHITE);
        textPaint.setAntiAlias(true);
        textPaint.setTypeface(Typeface.DEFAULT_BOLD);
        textPaint.setTextAlign(Paint.Align.CENTER);
        textPaint.setTextSize(SIZE_FACTOR * getIntrinsicHeight());
    }

    @Override
    public void draw(Canvas canvas) {
        super.draw(canvas);

        if (!enabled) {
            return;
        }

        final Rect bounds = getBounds();
        final float x = (1 - HALF_SIZE_FACTOR) * bounds.width();
        final float y = HALF_SIZE_FACTOR * bounds.height();
        canvas.drawCircle(x, y, SIZE_FACTOR * bounds.width(), backgroundPaint);

        if (text == null || text.length() == 0) {
            return;
        }

        final Rect textBounds = new Rect();
        textPaint.getTextBounds(text, 0, text.length(), textBounds);
        canvas.drawText(text, x, y + textBounds.height() / 2, textPaint);
    }

    public void setEnabled(boolean enabled) {
        if (this.enabled != enabled) {
            this.enabled = enabled;
            invalidateSelf();
        }
    }

    public boolean isEnabled() {
        return enabled;
    }

    public void setText(String text) {
        if (!Objects.equals(this.text, text)) {
            this.text = text;
            invalidateSelf();
        }
    }

    public String getText() {
        return text;
    }

    public void setBackgroundColor(int color) {
        if (backgroundPaint.getColor() != color) {
            backgroundPaint.setColor(color);
            invalidateSelf();
        }
    }

    public int getBackgroundColor() {
        return backgroundPaint.getColor();
    }

    public void setTextColor(int color) {
        if (textPaint.getColor() != color) {
            textPaint.setColor(color);
            invalidateSelf();
        }
    }

    public int getTextColor() {
        return textPaint.getColor();
    }
}

可以在实例化后的任何时间在切换上设置此实例,并根据需要直接在drawable上设置徽章的属性.

正如下面提到的OP,应该使用或者确保使用正确的样式值来使用Context自定义.例如:DrawerArrowDrawableActionBar#getThemedContext()Toolbar#getContext()

private ActionBarDrawerToggle toggle;
private BadgeDrawerArrowDrawable badgeDrawable;
...

toggle = new ActionBarDrawerToggle(this, ...);
badgeDrawable = new BadgeDrawerArrowDrawable(getSupportActionBar().getThemedContext());

toggle.setDrawerArrowDrawable(badgeDrawable);
badgeDrawable.setText("1");
...

为了简化一些事情,最好ActionBarDrawerToggle也是子类,并通过toggle实例处理所有事情.

import android.app.Activity;
import android.content.Context;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.Toolbar;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class BadgeDrawerToggle extends ActionBarDrawerToggle {

    private BadgeDrawerArrowDrawable badgeDrawable;

    public BadgeDrawerToggle(Activity activity, DrawerLayout drawerLayout,
                             int openDrawerContentDescRes,
                             int closeDrawerContentDescRes) {
        super(activity, drawerLayout, openDrawerContentDescRes,
              closeDrawerContentDescRes);
        init(activity);
    }

    public BadgeDrawerToggle(Activity activity, DrawerLayout drawerLayout,
                             Toolbar toolbar, int openDrawerContentDescRes,
                             int closeDrawerContentDescRes) {
        super(activity, drawerLayout, toolbar, openDrawerContentDescRes,
              closeDrawerContentDescRes);
        init(activity);
    }

    private void init(Activity activity) {
        Context c = getThemedContext();
        if (c == null) {
            c = activity;
        }
        badgeDrawable = new BadgeDrawerArrowDrawable(c);
        setDrawerArrowDrawable(badgeDrawable);
    }

    public void setBadgeEnabled(boolean enabled) {
        badgeDrawable.setEnabled(enabled);
    }

    public boolean isBadgeEnabled() {
        return badgeDrawable.isEnabled();
    }

    public void setBadgeText(String text) {
        badgeDrawable.setText(text);
    }

    public String getBadgeText() {
        return badgeDrawable.getText();
    }

    public void setBadgeColor(int color) {
        badgeDrawable.setBackgroundColor(color);
    }

    public int getBadgeColor() {
        return badgeDrawable.getBackgroundColor();
    }

    public void setBadgeTextColor(int color) {
        badgeDrawable.setTextColor(color);
    }

    public int getBadgeTextColor() {
        return badgeDrawable.getTextColor();
    }

    private Context getThemedContext() {
        // Don't freak about the reflection. ActionBarDrawerToggle
        // itself is already using reflection internally.
        try {
            Field mActivityImplField = ActionBarDrawerToggle.class
                .getDeclaredField("mActivityImpl");
            mActivityImplField.setAccessible(true);
            Object mActivityImpl = mActivityImplField.get(this);
            Method getActionBarThemedContextMethod = mActivityImpl.getClass()
                .getDeclaredMethod("getActionBarThemedContext");
            return (Context) getActionBarThemedContextMethod.invoke(mActivityImpl);
        }
        catch (Exception e) {
            return null;
        }
    }
}

这样,将自动设置自定义徽章drawable,并且可以通过单个对象管理与切换相关的所有内容.

BadgeDrawerToggle是一个替代品ActionBarDrawerToggle,其构造函数完全相同.

private BadgeDrawerToggle badgeToggle;
...

badgeToggle = new BadgeDrawerToggle(this, ...);
badgeToggle.setBadgeText("1");
...