Android tp的虚拟按键(virtual key)处理
Android tp的虚拟按键处理
现在在越来越多的Android的手机都是虚拟按键来操作,但是对于开发者来说可能会关心Android对虚拟按键如何处理的。对Linux熟悉的人可能会说,it's easy, 调用input_report_key()。OK,你说的没有错误,但是在android中,google让你对策略和驱动有了更加深入的了解。
APP------->
Framework------->
Kernel------->
Hardware
上面就是整个Android的Virtual key的整个的框图。
由于是搞驱动的,所以这里先从驱动开始说起。
其实说起对virtual key的处理对于驱动来说没有任何的难处,实现了Touch panel驱动,你也就将virtual key的底层驱动实现了。这里你试验了吗?你可能会说,“不行,这里实现不了”。是的,这个时候还不行,还有关键的步骤得操作。
在这里,你需要如下代码加入才可以。
static unsigned int tpd_keycnt = 0; static int tpd_keys[TPD_VIRTUAL_KEY_MAX]={0}; static int tpd_keys_dim[TPD_VIRTUAL_KEY_MAX][4];// = {0}; static ssize_t cust_virtual_keys_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { int i, j; for(i=0, j=0;i<tpd_keycnt;i++) j+=sprintf(buf, "%s%s:%d:%d:%d:%d:%d%s",buf, __stringify(EV_KEY),tpd_keys[i], tpd_keys_dim[i][0],tpd_keys_dim[i][1], tpd_keys_dim[i][2],tpd_keys_dim[i][3], (i==tpd_keycnt-1?"\n":":")); return j; } static struct kobj_attribute cust_virtual_keys_attr = { .attr = { .name = "virtualkeys.cust-tpd", .mode = S_IRUGO, }, .show = &cust_virtual_keys_show, }; static struct attribute *cust_properties_attrs[] = { &cust_virtual_keys_attr.attr, NULL }; static struct attribute_group cust_properties_attr_group = { .attrs = cust_properties_attrs, }; struct kobject *properties_kobj; void tpd_button_init(void) { int ret = 0, i = 0, j=0; tpd->kpd=input_allocate_device(); /* struct input_dev kpd initialization and registration */ tpd->kpd->name = TPD_DEVICE "-kpd"; set_bit(EV_KEY, tpd->kpd->evbit); for(i=0;i<tpd_keycnt;i++) __set_bit(tpd_keys[i], tpd->kpd->keybit); tpd->kpd->id.bustype = BUS_HOST; tpd->kpd->id.vendor = 0x0001; tpd->kpd->id.product = 0x0001; tpd->kpd->id.version = 0x0100; if(input_register_device(tpd->kpd)) TPD_DMESG("input_register_device failed.(kpd)\n"); set_bit(EV_KEY, tpd->dev->evbit); for(i=0;i<tpd_keycnt;i++) __set_bit(tpd_keys[i], tpd->dev->keybit); properties_kobj = kobject_create_and_add("board_properties", NULL); if(properties_kobj) ret = sysfs_create_group(properties_kobj,&cust_properties_attr_group); if(!properties_kobj || ret) printk("failed to create board_properties\n"); } void tpd_button_setting(int keycnt, void *keys, void *keys_dim) { tpd_keycnt = keycnt; memcpy(tpd_keys, keys, keycnt*4); memcpy(tpd_keys_dim, keys_dim, keycnt*4*4); }
有了上面的代码,我们的virtual key才可以使用,这里主要是需要注册/sys/board_properties/virtualkeys.cust-tpd。这个是framework需要的文件节点。他的出现可以使我们的虚拟按键畅通无阻了。
当然,在这里tpd_keys这个定义key的数组和定义区域的tpd_keys_dim要准确的填充才可以的。具体的填充的规则如下:
0x01: A version code. Must always be 0x01.
<Linux key code>: The Linux key code of the virtual key.
<centerX>: The X pixel coordinate of the center of the virtual key.
<centerY>: The Y pixel coordinate of the center of the virtual key.
<width>: The width of the virtual key in pixels.
<height>: The height of the virtual key in pixels.
对比我的milestone来看看:
0x01:158:32:906:63:57:
0x01:139:162:906:89:57:
0x01:102:292:906:89:57:
0x01:217:439:906:63:57
则可以看出定义了有back,menu,home,search,具体的区域也一清二楚了。
下面就是framework中的处理了,文件在framework/base/services/java/com/android/server/InputManager.java。
在其中通过调用getVirtualKeyDefinitions来获得定义的虚拟按键。
public VirtualKeyDefinition[] getVirtualKeyDefinitions(String deviceName) { ArrayList<VirtualKeyDefinition> keys = new ArrayList<VirtualKeyDefinition>(); try { FileInputStream fis = new FileInputStream( "/sys/board_properties/virtualkeys." + deviceName); InputStreamReader isr = new InputStreamReader(fis); BufferedReader br = new BufferedReader(isr, 2048); String str = br.readLine(); if (str != null) { String[] it = str.split(":"); if (DEBUG_VIRTUAL_KEYS) Slog.v(TAG, "***** VIRTUAL KEYS: " + it); final int N = it.length-6; for (int i=0; i<=N; i+=6) { if (!"0x01".equals(it[i])) { Slog.w(TAG, "Unknown virtual key type at elem #" + i + ": " + it[i] + " for device " + deviceName); continue; } try { VirtualKeyDefinition key = new VirtualKeyDefinition(); key.scanCode = Integer.parseInt(it[i+1]); key.centerX = Integer.parseInt(it[i+2]); key.centerY = Integer.parseInt(it[i+3]); key.width = Integer.parseInt(it[i+4]); key.height = Integer.parseInt(it[i+5]); if (DEBUG_VIRTUAL_KEYS) Slog.v(TAG, "Virtual key " + key.scanCode + ": center=" + key.centerX + "," + key.centerY + " size=" + key.width + "x" + key.height); keys.add(key); } catch (NumberFormatException e) { Slog.w(TAG, "Bad number in virtual key definition at region " + i + " in: " + str + " for device " + deviceName, e); } } } br.close(); } catch (FileNotFoundException e) { Slog.i(TAG, "No virtual keys found for device " + deviceName + "."); } catch (IOException e) { Slog.w(TAG, "Error reading virtual keys for device " + deviceName + ".", e); } return keys.toArray(new VirtualKeyDefinition[keys.size()]); }
其实找这个函数的调用的话,其实是发现通过JNI com_android_server_InputManager.cpp,InputReader.cpp来调用的。
最终通过notifyKey()来将key事件上报给app来处理。
在这其中还需要配置:
Key layout file: /system/usr/keylayout/touchyfeely.kl.
key 158 BACK
key 139 MENU
key 102 HOME
key 217 SEARCH
Key characte
补充:移动开发 , Android ,