前言

今天客戶提了個需求，因為我們的設(shè)備在正常情況下無法調(diào)節(jié)通話音量，只有在打電話過程中，按物理音量加減鍵才能出現(xiàn)調(diào)節(jié)通話音量seekBar，很不方便，于是乎需求就來了。需要優(yōu)化兩個地方

1、在正常情況下，按物理音量加減鍵都顯示 通話音量調(diào)節(jié)seekBar,可方便快速調(diào)節(jié)通話音量

2、在Settings中提示音界面點擊設(shè)置進入，增加通話音量調(diào)節(jié)seekBar

修改前

修改后

實現(xiàn)

第一個功能

先來完成第一個功能，還是通過Hierarchy View查看布局結(jié)構(gòu)，查找到布局文件id為volume_dialog，通過在源碼中搜索找到位于SystemUI中，volume_dialog.xml
源碼位置 frameworks\base\packages\SystemUI\res\layout\volume_dialog.xml

對應(yīng)的java類為 frameworks\base\packages\SystemUI\src\com\android\systemui\volume\VolumeDialog.java

修改代碼

addRow(AudioManager.STREAM_VOICE_CALL,
            R.drawable.ic_volume_voice, R.drawable.ic_volume_voice, true);

原來的第四個參數(shù)為false，修改為true即可顯示通話音量seekBar

為了便于說明，我們跟進addRow()中查看

private void addRow(int stream, int iconRes, int iconMuteRes, boolean important) {
    final VolumeRow row = initRow(stream, iconRes, iconMuteRes, important);
    if (!mRows.isEmpty()) {
        final View v = new View(mContext);
        v.setId(android.R.id.background);
        final int h = mContext.getResources()
                .getDimensionPixelSize(R.dimen.volume_slider_interspacing);
        final LinearLayout.LayoutParams lp =
                new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, h);
        mDialogContentView.addView(v, mDialogContentView.getChildCount() - 1, lp);
        row.space = v;
    }
	...
}

傳遞的參數(shù)對應(yīng)important，從字面意思理解重要對應(yīng)顯示，繼續(xù)查看initRow都做了什么

private VolumeRow initRow(final int stream, int iconRes, int iconMuteRes, boolean important) {
    final VolumeRow row = new VolumeRow();
    row.stream = stream;
    row.iconRes = iconRes;
    row.iconMuteRes = iconMuteRes;
    row.important = important;
    row.view = mDialog.getLayoutInflater().inflate(R.layout.volume_dialog_row, null);
    row.view.setTag(row);
    row.header = (TextView) row.view.findViewById(R.id.volume_row_header);
    mSpTexts.add(row.header);
    row.slider = (SeekBar) row.view.findViewById(R.id.volume_row_slider);
    row.slider.setOnSeekBarChangeListener(new VolumeSeekBarChangeListener(row));

    // forward events above the slider into the slider
    row.view.setOnTouchListener(new OnTouchListener() {
        private final Rect mSliderHitRect = new Rect();
        private boolean mDragging;

        @SuppressLint("ClickableViewAccessibility")
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            row.slider.getHitRect(mSliderHitRect);
            if (!mDragging && event.getActionMasked() == MotionEvent.ACTION_DOWN
                    && event.getY() < mSliderHitRect.top) {
                mDragging = true;
            }
            if (mDragging) {
                event.offsetLocation(-mSliderHitRect.left, -mSliderHitRect.top);
                row.slider.dispatchTouchEvent(event);
                if (event.getActionMasked() == MotionEvent.ACTION_UP
                        || event.getActionMasked() == MotionEvent.ACTION_CANCEL) {
                    mDragging = false;
                }
                return true;
            }
            return false;
        }
    });
    row.icon = (ImageButton) row.view.findViewById(R.id.volume_row_icon);
    row.icon.setImageResource(iconRes);
    row.icon.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            Events.writeEvent(mContext, Events.EVENT_ICON_CLICK, row.stream, row.iconState);
            mController.setActiveStream(row.stream);
            if (row.stream == AudioManager.STREAM_RING) {
                final boolean hasVibrator = mController.hasVibrator();
                if (mState.ringerModeInternal == AudioManager.RINGER_MODE_NORMAL) {
                    if (hasVibrator) {
                        mController.setRingerMode(AudioManager.RINGER_MODE_VIBRATE, false);
                    } else {
                        final boolean wasZero = row.ss.level == 0;
                        mController.setStreamVolume(stream, wasZero ? row.lastAudibleLevel : 0);
                    }
                } else {
                    mController.setRingerMode(AudioManager.RINGER_MODE_NORMAL, false);
                    if (row.ss.level == 0) {
                        mController.setStreamVolume(stream, 1);
                    }
                }
            } else {
                final boolean vmute = row.ss.level == 0;
                mController.setStreamVolume(stream, vmute ? row.lastAudibleLevel : 0);
            }
            row.userAttempt = 0;  // reset the grace period, slider should update immediately
        }
    });
    row.settingsButton = (ImageButton) row.view.findViewById(R.id.volume_settings_button);
    row.settingsButton.setOnClickListener(mClickSettings);
    return row;
}

從上面可看出，將一些變量都保存到了VolumeRow中，設(shè)置了icon的點擊事件，將當(dāng)前對應(yīng)的音量類型設(shè)置為最低(禁音), 設(shè)置seekBar的改變事件。通過過濾日志，查找到控制音量類型的顯示和隱藏的代碼塊updateRowsH()

private boolean isVisibleH(VolumeRow row, boolean isActive) {
    return mExpanded && row.view.getVisibility() == View.VISIBLE
            || (mExpanded && (row.important || isActive))
            || !mExpanded && isActive;
}

private void updateRowsH() {
    if (D.BUG) Log.d(TAG, "updateRowsH");
    final VolumeRow activeRow = getActiveRow();
    updateFooterH();
    updateExpandButtonH();
    if (!mShowing) {
        trimObsoleteH();
    }
    // apply changes to all rows
    for (VolumeRow row : mRows) {
        final boolean isActive = row == activeRow;
        final boolean visible = isVisibleH(row, isActive);
        Log.e(TAG, "row==" + row.stream + " isActive=="+isActive + " visible="+visible);
        Util.setVisOrGone(row.view, visible);
        Util.setVisOrGone(row.space, visible && mExpanded);
        final int expandButtonRes = mExpanded ? R.drawable.ic_volume_settings : 0;
        if (expandButtonRes != row.cachedExpandButtonRes) {
            row.cachedExpandButtonRes = expandButtonRes;
            if (expandButtonRes == 0) {
                row.settingsButton.setImageDrawable(null);
            } else {
                row.settingsButton.setImageResource(expandButtonRes);
            }
        }
        Util.setVisOrInvis(row.settingsButton, false);
        updateVolumeRowHeaderVisibleH(row);
        row.header.setAlpha(mExpanded && isActive ? 1 : 0.5f);
        updateVolumeRowSliderTintH(row, isActive);
    }
}

遍歷已經(jīng)添加的音量類型集合mRows，依次判斷是否處于活動狀態(tài)，再和開始設(shè)置的important屬性比較。mExpanded是否展開，默認(rèn)只顯示鈴聲音量控制，點擊下拉的按鈕，才完全顯示其它的音量控制

mExpanded && row.view.getVisibility() == View.VISIBLE || (mExpanded && (row.important || isActive)) || !mExpanded && isActive

true && false || (true && (true || false)) || false && true --->true

好了，至此分析完畢，重新mmm push SystemUI.apk 查看效果

第二個功能

源碼位置

Settings\res_ext\xml\edit_profile_prefs.xml
Settings\src\com\mediatek\audioprofile\Editprofile.java
Settings\src\com\mediatek\audioprofile\VolumeSeekBarPreference.java

在edit_profile_prefs.xml中仿照原來的Alarm volume和Ring volume，新增加一個Call volume

<!-- Media volume -->
<com.mediatek.audioprofile.VolumeSeekBarPreference
        android:key="media_volume"
        android:icon="@*android:drawable/ic_audio_vol"
        android:title="@string/media_volume_option_title" />

<!-- Alarm volume -->
<com.mediatek.audioprofile.VolumeSeekBarPreference
        android:key="alarm_volume"
        android:icon="@*android:drawable/ic_audio_alarm"
        android:title="@string/alarm_volume_option_title" />

<!-- Ring volume -->
<com.mediatek.audioprofile.VolumeSeekBarPreference
        android:key="ring_volume"
        android:icon="@*android:drawable/ic_audio_ring_notif"
        android:title="@string/ring_volume_option_title" />

<!-- Call volume -->
<com.mediatek.audioprofile.VolumeSeekBarPreference
        android:key="call_volume"
        android:icon="@drawable/ic_volume_voice"
        android:title="@string/call_volume_option_title" />

對應(yīng)的drawable文件時從SystemUI中拷貝過來的，ic_volume_voice.xml

<vector xmlns:android="http://schemas./apk/res/android"
android:height="24.0dp"
android:viewportHeight="48.0"
android:viewportWidth="48.0"
android:width="24.0dp" >

<path
    android:fillColor="#ff727272"
    android:pathData="M13.25,21.59c2.88,5.66 7.51,10.29 13.18,13.17l4.4,-4.41c0.55,-0.55 1.34,-0.71 2.03,-0.49C35.1,30.6 37.51,31.0 40.0,31.0c1.11,0.0 2.0,0.89 2.0,2.0l0.0,7.0c0.0,1.11 -0.89,2.0 -2.0,2.0C21.22,42.0 6.0,26.78 6.0,8.0c0.0,-1.1 0.9,-2.0 2.0,-2.0l7.0,0.0c1.11,0.0 2.0,0.89 2.0,2.0 0.0,2.4 0.4,4.9 1.14,7.1 0.2,0.6 0.06,1.48 -0.49,2.03l-4.4,4.42z" />

</vector>

接下來對應(yīng)到 Editprofile.java 文件中，可以看到 KEY_ALARM_VOLUME 對應(yīng)的preference初始化，依舊照葫蘆畫瓢，添加 KEY_CALL_VOLUME

private void initVolume(PreferenceScreen parent) {
    initVolumePreference(KEY_MEDIA_VOLUME, AudioManager.STREAM_MUSIC);
    initVolumePreference(KEY_ALARM_VOLUME, AudioManager.STREAM_ALARM);
    initVolumePreference(KEY_CALL_VOLUME, AudioManager.STREAM_VOICE_CALL);
    if (mVoiceCapable) {
        mVolume = initVolumePreference(KEY_RING_VOLUME, AudioManager.STREAM_RING);
        parent.removePreference(parent.findPreference(KEY_NOTIFICATION_VOLUME));
    } else {
        mVolume = initVolumePreference(KEY_NOTIFICATION_VOLUME,
                AudioManager.STREAM_NOTIFICATION);
        parent.removePreference(parent.findPreference(KEY_RING_VOLUME));
    }
}

重新編譯，push替換后發(fā)現(xiàn)，UI倒是出來了，但是無法滑動，事情果然沒那么簡單，繼續(xù)查看 initVolumePreference（）

private VolumeSeekBarPreference initVolumePreference(String key, int stream) {
    Log.d("@M_" + TAG, "Init volume preference, key = " + key + ",stream = " + stream);
    final VolumeSeekBarPreference volumePref = (VolumeSeekBarPreference) findPreference(key);
    volumePref.setStream(stream);
    volumePref.setCallback(mVolumeCallback);
    volumePref.setProfile(mKey);

    return volumePref;
}

保存了當(dāng)前的音量調(diào)節(jié)類型，設(shè)置seekBar回調(diào)事件，接下來看看回調(diào)處理了什么

private final class VolumePreferenceCallback implements VolumeSeekBarPreference.Callback {
    private SeekBarVolumizer mCurrent;

    @Override
    public void onSampleStarting(SeekBarVolumizer sbv) {
        if (mCurrent != null && mCurrent != sbv) {
            mCurrent.stopSample();
        }
        mCurrent = sbv;
        if (mCurrent != null) {
            mHandler.removeMessages(H.STOP_SAMPLE);
            mHandler.sendEmptyMessageDelayed(H.STOP_SAMPLE, SAMPLE_CUTOFF);
        }
    }

    public void onStreamValueChanged(int stream, int progress) {
        if (stream == AudioManager.STREAM_RING) {
            mHandler.removeMessages(H.UPDATE_RINGER_ICON);
            mHandler.obtainMessage(H.UPDATE_RINGER_ICON, progress, 0).sendToTarget();
        }
    }

    public void stopSample() {
        if (mCurrent != null) {
            mCurrent.stopSample();
        }
    }

    public void ringtoneChanged() {
        if (mCurrent != null) {
            mCurrent.ringtoneChanged();
        } else {
            mVolume.getSeekBar().ringtoneChanged();
        }
    }
};

當(dāng)我們點擊或者是滑動seekBar時，會根據(jù)當(dāng)前設(shè)置的音量大小播放一段短暫的默認(rèn)鈴音，當(dāng)鈴音未播放完成時，再次點擊將不進行播放。繼續(xù)跟進 VolumeSeekBarPreference.java 中

@Override
protected void onBindView(View view) {
    super.onBindView(view);
    if (mStream == 0) {
        Log.w(TAG, "No stream found, not binding volumizer  ");
        return;
    }
    getPreferenceManager().registerOnActivityStopListener(this);
    final SeekBar seekBar = (SeekBar) view.findViewById(com.android.internal.R.id.seekbar);
    if (seekBar == mSeekBar) {
        return;
    }
    mSeekBar = seekBar;
    final SeekBarVolumizer.Callback sbvc = new SeekBarVolumizer.Callback() {
        @Override
        public void onSampleStarting(SeekBarVolumizer sbv) {
            if (mCallback != null) {
                mCallback.onSampleStarting(sbv);
            }
        }
    };
    final Uri sampleUri = mStream == AudioManager.STREAM_MUSIC ? getMediaVolumeUri() : null;
    if (mVolumizer == null) {
        mVolumizer = new SeekBarVolumizer(getContext(), mStream, sampleUri, sbvc, mKey);
    }
    //mVolumizer.setProfile(mKey);
    mVolumizer.setSeekBar(mSeekBar);
}

mStream == 0, 直接return，會不會和這有關(guān)系呢，來看下各個音量調(diào)節(jié)類型對應(yīng)的int值

/** Used to identify the volume of audio streams for phone calls */
public static final int STREAM_VOICE_CALL = 0;
/** Used to identify the volume of audio streams for the phone ring and message alerts */
public static final int STREAM_RING = 2;
/** Used to identify the volume of audio streams for music playback */
public static final int STREAM_MUSIC = 3;
/** Used to identify the volume of audio streams for alarms */
public static final int STREAM_ALARM = 4;

我們新增的 STREAM_VOICE_CALL對應(yīng)的mStream正好為0，直接給return掉了，所以修改為 mStream < 0 即可，重新編譯 push 發(fā)現(xiàn)成功了。

具體的音量調(diào)節(jié)邏輯在 packages\apps\Settings\src\com\mediatek\audioprofile\SeekBarVolumizer.java 中，感興趣的可繼續(xù)深究，肯定離不開調(diào)用 .setStreamVolume()方法，大概看了一眼，主要是onProgressChanged()回調(diào)，通過postSetVolume(progress)方法，發(fā)送MSG_SET_STREAM_VOLUME消息，最終調(diào)用saveVolume()