Launcher making 20210123

1:  在android 清单文件中添加过滤条件

<activity android:name=".MainActivity">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
        <category android:name="android.intent.category.MONKEY" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.HOME" />
    </intent-filter>
</activity>

 

2: 构建数据库 相关的资料，数据data

iteminfo

package com.kodulf.mylauncher.data;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.UserHandle;
import android.os.UserManager;
import android.util.Log;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

/**
 * Represents an item in the launcher.
 */
class ItemInfo {

    static final int NO_ID = -1;
    /**
    Fix 这里需要用的是long
     */
    long id = NO_ID;
    String title;
    /**
    启动的意图
     */
    String intent;

    int screenId = -1;
    /**
    application，shortcut，widget
     */
    int itemType = -1;
    /**
        hotseat，workspace，folder
     */
    int container = NO_ID;

    /**
     * x的格子数
     */
    int X = 1;
    /**
     * y的格子数
     */
    int Y = 1;
    /**
    所占的x的宽度，几个行格子
     */
    int spanX = 1;
    /**
    所占的y的宽度，几个列格子
     */
    int spanY = 1;
    /**
    最小的span的宽度跨越的格数
     */
    int minSpanX = 1;
    /**
     最小的span的高度跨越的格数
     */
    int minSpanY = 1;


    /**
     * 当前的用户
     */
    UserHandle user;

    ItemInfo(){
        //获取当前的用户
        user = android.os.Process.myUserHandle();
    }

    @Override
    public String toString() {
        return "ItemInfo{" +
                "id=" + id +
                ", title='" + title + '\'' +
                ", intent='" + intent + '\'' +
                ", screenId=" + screenId +
                ", itemType=" + itemType +
                ", container=" + container +
                ", X=" + X +
                ", Y=" + Y +
                ", spanX=" + spanX +
                ", spanY=" + spanY +
                ", minSpanX=" + minSpanX +
                ", minSpanY=" + minSpanY +
                ", user=" + user +
                '}';
    }


    //todo 下面是没有用到的原生里面的内容
    /*

    static final String EXTRA_PROFILE = "profile";

    static final int NO_ID = -1;

    没有用到的原生的
    boolean requiresDbUpdate = false;

    CharSequence contentDescription;
    int[] dropPos = null;

      ItemInfo() {
        user = android.os.Process.myUserHandle();
    }

    ItemInfo(ItemInfo info) {
        id = info.id;
        cellX = info.cellX;
        cellY = info.cellY;
        spanX = info.spanX;
        spanY = info.spanY;
        screen = info.screen;
        itemType = info.itemType;
        container = info.container;
        user = info.user;
        contentDescription = info.contentDescription;
        // tempdebug:
        LauncherModel.checkItemInfo(this);
    }

     Returns the package name that the intent will resolve to, or an empty string if
     *  none exists.
    static String getPackageName(Intent intent) {
        if (intent != null) {
            String packageName = intent.getPackage();
            if (packageName == null && intent.getComponent() != null) {
                packageName = intent.getComponent().getPackageName();
            }
            if (packageName != null) {
                return packageName;
            }
        }
        return "";
    }

    protected void updateUser(Intent intent) {
        if (intent != null && intent.hasExtra(EXTRA_PROFILE)) {
            user = (UserHandle) intent.getParcelableExtra(EXTRA_PROFILE);
        }
    }


     * Write the fields of this item to the DB
     *
     * @param context A context object to use for getting a UserManager
     *            instance.
     * @param values

    void onAddToDatabase(Context context, ContentValues values) {
        values.put(LauncherSettings.BaseLauncherColumns.ITEM_TYPE, itemType);
        values.put(LauncherSettings.Favorites.CONTAINER, container);
        values.put(LauncherSettings.Favorites.SCREEN, screen);
        values.put(LauncherSettings.Favorites.CELLX, cellX);
        values.put(LauncherSettings.Favorites.CELLY, cellY);
        values.put(LauncherSettings.Favorites.SPANX, spanX);
        values.put(LauncherSettings.Favorites.SPANY, spanY);
        long serialNumber = ((UserManager) context.getSystemService(Context.USER_SERVICE))
                .getSerialNumberForUser(user);
        values.put(LauncherSettings.Favorites.PROFILE_ID, serialNumber);
    }

    void updateValuesWithCoordinates(ContentValues values, int cellX, int cellY) {
        values.put(LauncherSettings.Favorites.CELLX, cellX);
        values.put(LauncherSettings.Favorites.CELLY, cellY);
    }

    static byte[] flattenBitmap(Bitmap bitmap) {
        // Try go guesstimate how much space the icon will take when serialized
        // to avoid unnecessary allocations/copies during the write.
        int size = bitmap.getWidth() * bitmap.getHeight() * 4;
        ByteArrayOutputStream out = new ByteArrayOutputStream(size);
        try {
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
            out.flush();
            out.close();
            return out.toByteArray();
        } catch (IOException e) {
            Log.w("Favorite", "Could not write icon");
            return null;
        }
    }

    static void writeBitmap(ContentValues values, Bitmap bitmap) {
        if (bitmap != null) {
            byte[] data = flattenBitmap(bitmap);
            values.put(LauncherSettings.Favorites.ICON, data);
        }
    }


     * It is very important that sub-classes implement this if they contain any references
     * to the activity (anything in the view hierarchy etc.). If not, leaks can result since
     * ItemInfo objects persist across rotation and can hence leak by holding stale references
     * to the old view hierarchy / activity.

    void unbind() {
    }

     */


}