自己写的SeekBarPreference,可以实现seekbar滑动监听和设置默认进度和最大进度

技术文章

我通过参考android源码,把这个烂尾的类写完了。具体实现了seekbar的数据自动存储,seekbar拖动时触发监听器,可以设置默认的进度和最大进度。先说使用的方式:

 

1.在xml文件中使用preference

<com.kale.floatbar.preference.MySeekBarPreference
            android:key="alpha"
            android:layout="@layout/prefs_list_item"
            android:title="透明度" />

 

2,在Java代码中找到preference然后设置数值或绑定监听器

      private MySeekBarPreference alphaSb
        alphaSb = (MySeekBarPreference) findPreference("alpha");//找到preference
        alphaSb.setDefaultProgressValue(100);//设置起始时的进度
        alphaSb.setMax(255);//设置最大的数值,不超过10000。如果超过了请在seekbarPreference源码中进行修改max值
        alphaSb.setOnSeekBarPrefsChangeListener(this);//设置监听器

 

3.设置监听器,这里的key是当前触发监听器的preference的key,这样可以区分是哪个seekbarPreference触发的监听器

    @Override
    public void onStopTrackingTouch(String key, SeekBar seekBar) {
    }

    @Override
    public void onStartTrackingTouch(String key, SeekBar seekBar) {
    }

    @Override
    public void onProgressChanged(String key, SeekBar seekBar, int progress, boolean fromUser) {
        
    }

 

最后是SeekbarPreference的源码:

/*
 * Copyright (C) 2011 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 com.kale.floatbar.preference;

import android.content.Context;
import android.os.Parcel;
import android.os.Parcelable;
import android.preference.Preference;
import android.util.AttributeSet;
import android.view.View;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;

import com.kale.floatbar.R;



public class MySeekBarPreference extends Preference implements OnSeekBarChangeListener{
    
    private TextView value;
    private int mProgress;
    private int mMax = 10000;//如果您的seekbar最大值超过了10000,那么在这里修改下即可。否则会被限制最大值为10000
    private boolean mTrackingTouch;
    private OnSeekBarPrefsChangeListener mListener = null;
    
    public MySeekBarPreference(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        
        setMax(mMax);
        setLayoutResource(R.layout.seekbar_prefs);
    }

    public MySeekBarPreference(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MySeekBarPreference(Context context) {
        this(context, null);
    }
    
    @Override
    protected void onBindView(View view) {
        super.onBindView(view);

        SeekBar seekBar = (SeekBar) view.findViewById(R.id.seekbar);
        seekBar.setMax(mMax);
        seekBar.setProgress(mProgress);
        seekBar.setEnabled(isEnabled());
        seekBar.setOnSeekBarChangeListener(this);
        value = (TextView)view.findViewById(R.id.value);
        value.setText(String.valueOf(mProgress));
    }

    /** 设置默认的值
     * @param defaultValue
     */
    public void setDefaultProgressValue(int defaultValue) {
        if(getPersistedInt(-1) == -1) {
            //说明没有用户设定的值,所以设置初始值
            setProgress(defaultValue);
        }
    }
    
    @Override
    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
        setProgress(restoreValue ? getPersistedInt(mProgress): (Integer) defaultValue);
    }

    public void setMax(int max) {
        if (max != mMax) {
            mMax = max;
            notifyChanged();
        }
    }

    public void setProgress(int progress) {
        setProgress(progress, true);
    }

    private void setProgress(int progress, boolean notifyChanged) {
        if (progress > mMax) {
            progress = mMax;
        }
        if (progress < 0) {
            progress = 0;
        }
        if (progress != mProgress) {
            mProgress = progress;
            persistInt(progress);
            if (notifyChanged) {
                notifyChanged();
            }
        }
    }

    public int getProgress() {
        return mProgress;
    }

    public void setOnSeekBarPrefsChangeListener(OnSeekBarPrefsChangeListener listener) {
        mListener = listener;
    }
    
    /**
     * @author:Jack Tony
     * @tips  :设置监听器
     * @date  :2014-8-17
     */
    public interface OnSeekBarPrefsChangeListener {
        //public void OnSeekBarChangeListener(SeekBar seekBar, boolean isChecked);
        public void onStopTrackingTouch(String key ,SeekBar seekBar) ;
        public void onStartTrackingTouch(String key ,SeekBar seekBar);
        public void onProgressChanged(String key ,SeekBar seekBar, int progress,boolean fromUser);
    }
    
    /**
     * Persist the seekBar‘s progress value if callChangeListener
     * returns true, otherwise set the seekBar‘s progress to the stored value
     */
    void syncProgress(SeekBar seekBar) {
        int progress = seekBar.getProgress();
        if (progress != mProgress) {
            if (callChangeListener(progress)) {
                setProgress(progress, false);
            } else {
                seekBar.setProgress(mProgress);
            }
        }
    }

    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        //value.setText(seekBar.getProgress()+"");
        if (mListener != null) {
            mListener.onProgressChanged(getKey(),seekBar, progress, fromUser);
        }
        if (seekBar.getProgress() != mProgress) {
            syncProgress(seekBar);
        }
        if (fromUser && !mTrackingTouch) {
            syncProgress(seekBar);
        }
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {
        if (mListener != null) {
            mListener.onStartTrackingTouch(getKey(),seekBar);
        }
        mTrackingTouch = true;
    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
        if (mListener != null) {
            mListener.onStopTrackingTouch(getKey(),seekBar);
        }
        mTrackingTouch = false;
        if (seekBar.getProgress() != mProgress) {
            syncProgress(seekBar);
        }
        notifyHierarchyChanged();
    }

    @Override
    protected Parcelable onSaveInstanceState() {
        /*
         * Suppose a client uses this preference type without persisting. We
         * must save the instance state so it is able to, for example, survive
         * orientation changes.
         */

        final Parcelable superState = super.onSaveInstanceState();
        if (isPersistent()) {
            // No need to save instance state since it‘s persistent
            return superState;
        }

        // Save the instance state
        final SavedState myState = new SavedState(superState);
        myState.progress = mProgress;
        myState.max = mMax;
        return myState;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {
        if (!state.getClass().equals(SavedState.class)) {
            // Didn‘t save state for us in onSaveInstanceState
            super.onRestoreInstanceState(state);
            return;
        }

        // Restore the instance state
        SavedState myState = (SavedState) state;
        super.onRestoreInstanceState(myState.getSuperState());
        mProgress = myState.progress;
       
        mMax = myState.max;
        notifyChanged();
    }

    /**
     * SavedState, a subclass of {@link BaseSavedState}, will store the state
     * of MyPreference, a subclass of Preference.
     * <p>
     * It is important to always call through to super methods.
     */
    private static class SavedState extends BaseSavedState {
        int progress;
        int max;

        public SavedState(Parcel source) {
            super(source);
            // Restore the click counter
            progress = source.readInt();
            max = source.readInt();
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            super.writeToParcel(dest, flags);
            // Save the click counter
            dest.writeInt(progress);
            dest.writeInt(max);
        }

        public SavedState(Parcelable superState) {
            super(superState);
        }

    }
}

 

文章来自:http://www.cnblogs.com/tianzhijiexian/p/3987766.html
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