Question

我正在查看Instances Content Provider的安卓日历源代码，看看它是如何工作的并填充。

原因是我试图在我的应用程序中复制其工作方式，但我还没有找到它在源代码中填充的位置。

我知道Instances数据库无法写入，但是在它填充之后必须要写入它的某个地方。我只想看看他们如何对这些值进行一些计算。

关于Instances我唯一能找到的是this，但这并没有告诉我我想知道什么，只是告诉我query和{{1}不是值背后的代码。

有谁知道它在哪里？

Answer 1

处理以content://com.android.calendar/instances/*开头的内容提供商URI的代码位于packages/providers/CalendarProvider/src/com/android/providers/calendar/CalendarProvider2.java。

从该文件中可以查找更多实施细节。例如，许多初始化代码（如CREATE TABLE调用）位于同一项目的CalendarDatabaseHelper.java中。

我希望这有帮助！

Answer 2

实例正在 CalendarInstancesHelper.java 中的“ updateInstancesLocked ”方法中填充。另请在同一文件中查看“ performInstanceExpansion ”方法。

在GrepCode

中链接上述方法

我提供了以下方法的摘录

  /**
 * Updates the instances table when an event is added or updated.
 * @param values The new values of the event.
 * @param rowId The database row id of the event.
 * @param newEvent true if the event is new.
 * @param db The database
 */
private void updateInstancesLocked(ContentValues values,
        long rowId,
        boolean newEvent,
        SQLiteDatabase db) {

    // If there are no expanded Instances, then return.
    MetaData.Fields fields = mMetaData.getFieldsLocked();
    if (fields.maxInstance == 0) {
        return;
    }

    Long dtstartMillis = values.getAsLong(Events.DTSTART);
    if (dtstartMillis == null) {
        if (newEvent) {
            // must be present for a new event.
            throw new RuntimeException("DTSTART missing.");
        }
        if (Log.isLoggable(TAG, Log.VERBOSE)) {
            Log.v(TAG, "Missing DTSTART.  No need to update instance.");
        }
        return;
    }

    Long lastDateMillis = values.getAsLong(Events.LAST_DATE);
    Long originalInstanceTime = values.getAsLong(Events.ORIGINAL_INSTANCE_TIME);

    if (!newEvent) {
        // Want to do this for regular event, recurrence, or exception.
        // For recurrence or exception, more deletion may happen below if we
        // do an instance expansion.  This deletion will suffice if the exception
        // is moved outside the window, for instance.
        db.delete("Instances", "event_id=?", new String[] {String.valueOf(rowId)});
    }

    String rrule = values.getAsString(Events.RRULE);
    String rdate = values.getAsString(Events.RDATE);
    String originalEvent = values.getAsString(Events.ORIGINAL_EVENT);
    if (isRecurrenceEvent(rrule, rdate, originalEvent))  {
        // The recurrence or exception needs to be (re-)expanded if:
        // a) Exception or recurrence that falls inside window
        boolean insideWindow = dtstartMillis <= fields.maxInstance &&
                (lastDateMillis == null || lastDateMillis >= fields.minInstance);
        // b) Exception that affects instance inside window
        // These conditions match the query in getEntries
        //  See getEntries comment for explanation of subtracting 1 week.
        boolean affectsWindow = originalInstanceTime != null &&
                originalInstanceTime <= fields.maxInstance &&
                originalInstanceTime >= fields.minInstance - MAX_ASSUMED_DURATION;
        if (insideWindow || affectsWindow) {
            updateRecurrenceInstancesLocked(values, rowId, db);
        }
        // TODO: an exception creation or update could be optimized by
        // updating just the affected instances, instead of regenerating
        // the recurrence.
        return;
    }

    Long dtendMillis = values.getAsLong(Events.DTEND);
    if (dtendMillis == null) {
        dtendMillis = dtstartMillis;
    }

    // if the event is in the expanded range, insert
    // into the instances table.
    // TODO: deal with durations.  currently, durations are only used in
    // recurrences.

    if (dtstartMillis <= fields.maxInstance && dtendMillis >= fields.minInstance) {
        ContentValues instanceValues = new ContentValues();
        instanceValues.put(Instances.EVENT_ID, rowId);
        instanceValues.put(Instances.BEGIN, dtstartMillis);
        instanceValues.put(Instances.END, dtendMillis);

        boolean allDay = false;
        Integer allDayInteger = values.getAsInteger(Events.ALL_DAY);
        if (allDayInteger != null) {
            allDay = allDayInteger != 0;
        }

        // Update the timezone-dependent fields.
        Time local = new Time();
        if (allDay) {
            local.timezone = Time.TIMEZONE_UTC;
        } else {
            local.timezone = fields.timezone;
        }

        computeTimezoneDependentFields(dtstartMillis, dtendMillis, local, instanceValues);
        mDbHelper.instancesInsert(instanceValues);
    }
}

希望这有帮助!!!

如果您期待不同的事情，请告诉我

日历实例提供程序源代码？

2 个答案: