Android Toast advanced-custom Toast

Android Toast advanced-custom Toast
Directory structure

Directory structure preface advanced target control Toast display time modification Toast animation effect

Preface

CSDN actually supports the Markdown syntax. It is really good news for me who are too lazy to build my own blog. When I review the Markdown syntax, i'm going to rewrite the previous Android Toast advanced with the Markdown syntax.

Advanced Objectives

In the previous blog, we learned the source code of Toast and the entire process from display to disappearance of Toast. Link: Android Toast source code analysis. As the saying goes, it's a good practice. The source code of Toast is not used to demonstrate the technology, but to understand the Toast principle, so as to truly solve our problem. Next I will mention the real issues related to Toast that may be encountered in the two businesses. Let's take a look at how to solve these problems after learning the Toast source code. There are two problems:
1. How to customize the display time of Toast.
2. Modify the animation of Toast.
Next, we will explain how to solve the real problems encountered in these two businesses after reading the Toast source code.

Controls the display time of Toast

By studying the Toast source code, we know that Toast display and disappearance are implemented by icationicationmanagerservice calling the show and hide methods of the TN class, the length of Toast display time is related to the delay time when Handler sends messages. The source code is as follows:

private void scheduleTimeoutLocked(ToastRecord r){    mHandler.removeCallbacksAndMessages(r);    Message m = Message.obtain(mHandler, MESSAGE_TIMEOUT, r);    long delay = r.duration == Toast.LENGTH_LONG ? LONG_DELAY : SHORT_DELAY;    mHandler.sendMessageDelayed(m, delay);}

Previously, I also mentioned in the Toast source code that the Toast desktop display time can only be 2 s and 3.5 s. The key is that the delay time of the long delay variable can only be 2 s and 3.5 s. Therefore, if you are a developer of the Android operating system, you can directly modify the icationicationmanagerservice class code of the Android Framework layer and change LONG_DELAY and SHORT_DELAY to the desired time interval. However, this practice has obvious drawbacks. First, you may be just a small application-layer development engineer who can only change the application-layer code. Second, even if icationicationmanagerservice is modified, only the LONG_DELAY and SHORT_DELAY variables can be modified, and the display time cannot be modified at will.
What should we do when there are so many drawbacks? The answer is also very simple. Like the Toast source code, we can create a wheel and customize a Toast. In this way, we can certainly control the display time of Toast. We know from the source code that Toast is displayed based on WindowManager, so we can define a custom Toast. The source code is as follows:

import android.content.Context;import android.graphics.PixelFormat;import android.os.Handler;import android.os.Message;import android.view.Gravity;import android.view.View;import android.view.WindowManager;import android.widget.Toast;public class ToastCustom {    private static final int MESSAGE_TIMEOUT = 2;    private WindowManager wdm;    private double time;    private View mView;    private WindowManager.LayoutParams params;    private WorkerHandler mHandler;    private ToastCustom(Context context, String text, double time) {        wdm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);        mHandler = new WorkerHandler();        Toast toast = Toast.makeText(context, text, Toast.LENGTH_LONG);        mView = toast.getView();        params = new WindowManager.LayoutParams();        params.height = WindowManager.LayoutParams.WRAP_CONTENT;        params.width = WindowManager.LayoutParams.WRAP_CONTENT;        params.format = PixelFormat.TRANSLUCENT;        params.windowAnimations = toast.getView().getAnimation().INFINITE;        params.type = WindowManager.LayoutParams.TYPE_TOAST;        params.setTitle("Toast");        params.gravity = Gravity.CENTER_HORIZONTAL | Gravity.CENTER_VERTICAL;        params.flags = WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON                | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE                | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;        this.time = time;    }    public static ToastCustom makeText(Context context, String text, double time) {        ToastCustom toastCustom = new ToastCustom(context, text, time);        return toastCustom;    }    public void show() {        wdm.addView(mView, params);        mHandler.sendEmptyMessageDelayed(MESSAGE_TIMEOUT, (long) (time * 1000));    }    public void cancel() {        wdm.removeView(mView);    }    private class WorkerHandler extends Handler {        @Override        public void handleMessage(Message msg)        {            switch (msg.what)            {                case MESSAGE_TIMEOUT:                    cancel();                    break;            }        }    }}

The principle is very simple. Use WindowManager to display Toast, and then use Handler to send delayed messages to control WindowManager and then delete Toast. Note: here, the Handler of the custom Toast is also the Logoff of the main thread. When the sub-thread calls the custom Toast, the loast. prepare () and loast. loop () codes need to be added.

Modify the Toast animation effect

The Android native Toast class does not provide an interface for us to set the animation effect. The animation effect of each Android native Toast is defined in the TN class com. android. internal. r. style. animation_Toast, so if you want to modify Android? For the animation effect of Toast, you still need to upload a Toast and modify the content of the params. windowAnimations variable. Next, let's first customize an animation effect. Define a new style in the style. xml file. The xml content is as follows:

Then add two animation effect files under the anim Folder: enter_anim.xml and exit_anim.xml.

Enter_anim.xml

Exit_anim.xml

Then, modify the params. windowAnimations variable in the Custom Toast code:

params.windowAnimations = com.example.photocrop.R.style.custom_toast_anim_view;