在我們三星s5pv210平台上使用的Android2.3.4內建的browser無法開啟網頁後進行兩指手勢縮放操作,只能通過連擊縮放,而其他平台都可以,後來發現問題在frameworks/base/core/java/android/webkit/WebView.java檔案的如下函數中:
void
updateMultiTouchSupport(Context context) {
WebSettings settings = getSettings();
final PackageManager pm =
context.getPackageManager();
mSupportMultiTouch =
pm.hasSystemFeature(PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH) &&
settings.supportZoom() &&
settings.getBuiltInZoomControls();
mAllowPanAndScale = pm.hasSystemFeature(
PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH_DISTINCT);
if (mSupportMultiTouch
&& (mScaleDetector == null))
mScaleDetector = new ScaleGestureDetector(context,new
ScaleDetectorListener());
} else if (!mSupportMultiTouch
&& (mScaleDetector != null))
mScaleDetector = null; 查了下,mSupportMultiTouch這個變數是決定性因素,而其又決定於下面三大條件:
1、PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH;
2、settings.supportZoom();
3、settings.getBuiltInZoomControls();
後面兩個函數對應於mSupportZoom和mBuiltInZoomControls兩變數,查到在裡面相應的設定都會為true,故問題存在於第一點,該點取決於/system/etc/permissions/目錄下的檔案,只有其中有一個xml檔案裡含有android.hardware.touchscreen.multitouch這項就要吧,後來發現原來我們的檔案系統對應的目錄下是不存在相應的檔案,再查下去發現在我們的frameworks/base/data/etc/目錄下有檔案android.hardware.touchscreen.multitouch.xml,含有如下內容:
<permissions>
<feature
name="android.hardware.touchscreen" />
<feature
name="android.hardware.touchscreen.multitouch"
/>
</permissions>
現在,我們在編譯的指令碼中讓其每次都複製到/system/etc/permissions/目錄下即可,修改device/samsung/smdkv210/device.mk檔案,在任一項PRODUCT_COPY_FILES frameworks/base/data/etc/android.hardware.touchscreen.multitouch.xml:system/etc/permissions/android.hardware.touchscreen.multitouch.xml,至此就搞定了,為何只要含有上面的配置項即能讓PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH這個特性生效,首先取決於硬體,TP要支援兩點以上觸摸,再者取決於檔案frameworks/base/services/java/com/android/server/PackageManagerService.java,該檔案會讀取複製的目標目錄下的xml,並配置相應的參數。 參考網址:http://blog.csdn.net/tjd0227/article/details/6043206 http://www.bangchui.org/simple/?t8649.html