platform_system_core/include/utils/Printer.h

120 lines
3.7 KiB
C++

/*
* Copyright (C) 2013 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.
*/
#ifndef ANDROID_PRINTER_H
#define ANDROID_PRINTER_H
#include <android/log.h>
namespace android {
// Interface for printing to an arbitrary data stream
class Printer {
public:
// Print a new line specified by 'string'. \n is appended automatically.
// -- Assumes that the string has no new line in it.
virtual void printLine(const char* string = "") = 0;
// Print a new line specified by the format string. \n is appended automatically.
// -- Assumes that the resulting string has no new line in it.
virtual void printFormatLine(const char* format, ...) __attribute__((format (printf, 2, 3)));
protected:
Printer();
virtual ~Printer();
}; // class Printer
// Print to logcat
class LogPrinter : public Printer {
public:
// Create a printer using the specified logcat and log priority
// - Unless ignoreBlankLines is false, print blank lines to logcat
// (Note that the default ALOG behavior is to ignore blank lines)
LogPrinter(const char* logtag,
android_LogPriority priority = ANDROID_LOG_DEBUG,
const char* prefix = 0,
bool ignoreBlankLines = false);
// Print the specified line to logcat. No \n at the end is necessary.
virtual void printLine(const char* string);
private:
void printRaw(const char* string);
const char* mLogTag;
android_LogPriority mPriority;
const char* mPrefix;
bool mIgnoreBlankLines;
}; // class LogPrinter
// Print to a file descriptor
class FdPrinter : public Printer {
public:
// Create a printer using the specified file descriptor.
// - Each line will be prefixed with 'indent' number of blank spaces.
// - In addition, each line will be prefixed with the 'prefix' string.
FdPrinter(int fd, unsigned int indent = 0, const char* prefix = 0);
// Print the specified line to the file descriptor. \n is appended automatically.
virtual void printLine(const char* string);
private:
enum {
MAX_FORMAT_STRING = 20,
};
int mFd;
unsigned int mIndent;
const char* mPrefix;
char mFormatString[MAX_FORMAT_STRING];
}; // class FdPrinter
class String8;
// Print to a String8
class String8Printer : public Printer {
public:
// Create a printer using the specified String8 as the target.
// - In addition, each line will be prefixed with the 'prefix' string.
// - target's memory lifetime must be a superset of this String8Printer.
String8Printer(String8* target, const char* prefix = 0);
// Append the specified line to the String8. \n is appended automatically.
virtual void printLine(const char* string);
private:
String8* mTarget;
const char* mPrefix;
}; // class String8Printer
// Print to an existing Printer by adding a prefix to each line
class PrefixPrinter : public Printer {
public:
// Create a printer using the specified printer as the target.
PrefixPrinter(Printer& printer, const char* prefix);
// Print the line (prefixed with prefix) using the printer.
virtual void printLine(const char* string);
private:
Printer& mPrinter;
const char* mPrefix;
};
}; // namespace android
#endif // ANDROID_PRINTER_H