MacGui: Proposal for replacing UpdateUI timer in HBController. HBCore…

… is a more ObjC-like interface to the core libhb library. It provides notifications of libhb state changes via NSNotificationCenter. Interfaces for scanning, encoding, bindings etc. can be added later. Note: this class is not used in HB (yet).

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@605 b64f7644-9d1e-0410-96f1-a4d463321fa5

macosx/HBCore.h

@@ -0,0 +1,52 @@
+/**
+ * @file
+ * Interface of class HBCore.
+ */
+
+#import <Cocoa/Cocoa.h>
+
+extern const NSString *HBStateIdle;
+extern const NSString *HBStateScanning;
+extern const NSString *HBStateScanDone;
+extern const NSString *HBStateWorking;
+extern const NSString *HBStatePaused;
+extern const NSString *HBStateWorkDone;
+extern const NSString *HBStateMuxing;
+extern const NSString *HBStateAll;
+
+extern NSString *HBCoreScanningNotification;
+extern NSString *HBCoreScanDoneNotification;
+extern NSString *HBCoreWorkingNotification;
+extern NSString *HBCorePausedNotification;
+extern NSString *HBCoreWorkDoneNotification;
+extern NSString *HBCoreMuxingNotification;
+
+/**
+ * HBCore is an Objective-C interface to the low-level HandBrake library.
+ * HBCore monitors state changes of libhb and provides notifications via
+ * NSNotificationCenter to any object who needs them. It can also be used
+ * to implement properties that can be directly bound to elements of the gui.
+ */
+@interface HBCore : NSObject
+{
+    /// Pointer to libhb handle.
+    struct hb_handle_s *hb_handle;
+
+    /// Pointer to latest state information returned by libhb.
+    struct hb_state_s *hb_state;
+
+    /// Timer used to poll libhb for state changes.
+    NSTimer *updateTimer;
+
+    /// Current state of HBCore; one of the HBState* constants.
+    const NSString *state;  
+}
+
+- (id)init;
+- (BOOL)openInDebugMode:(BOOL)debugMode checkForUpdates:(BOOL)checkForUpdates;
+- (BOOL)close;
+- (NSString *)state;
+- (struct hb_handle_s *)hb_handle;
+- (const struct hb_state_s *)hb_state;
+
+@end

macosx/HBCore.m

@@ -0,0 +1,271 @@
+/**
+ * @file
+ * Implementation of class HBCore.
+ */
+
+#import "HBCore.h"
+#include "hb.h"
+
+// These constants specify the current state of HBCore.
+
+const NSString *HBStateIdle = @"HBStateIdle";           ///< HB is doing nothing (HB_STATE_IDLE)
+const NSString *HBStateScanning = @"HBStateScanning";   ///< HB is scanning (HB_STATE_SCANNING)
+const NSString *HBStateScanDone = @"HBStateScanDone";   ///< Scanning has been completed (HB_STATE_SCANDONE)
+const NSString *HBStateWorking = @"HBStateWorking";     ///< HB is encoding (HB_STATE_WORKING)
+const NSString *HBStatePaused = @"HBStatePaused";       ///< Encoding is paused (HB_STATE_PAUSED)
+const NSString *HBStateWorkDone = @"HBStateWorkDone";   ///< Encoding has been completed (HB_STATE_WORKDONE)
+const NSString *HBStateMuxing = @"HBStateMuxing";       ///< HB is muxing (HB_STATE_MUXING)
+
+
+// These constants specify various status notifications sent by HBCore
+
+/// Notification sent to update status while scanning. Matches HB_STATE_SCANNING constant in libhb.
+NSString *HBCoreScanningNotification = @"HBCoreScanningNotification";
+
+/// Notification sent after scanning is complete. Matches HB_STATE_SCANDONE constant in libhb.
+NSString *HBCoreScanDoneNotification = @"HBCoreScanDoneNotification";
+
+/// Notification sent to update status while encoding. Matches HB_STATE_WORKING constant in libhb.
+NSString *HBCoreWorkingNotification = @"HBCoreWorkingNotification";
+
+/// Notification sent when encoding is paused. Matches HB_STATE_PAUSED constant in libhb.
+NSString *HBCorePausedNotification = @"HBCorePausedNotification";
+
+/// Notification sent after encoding is complete. Matches HB_STATE_WORKDONE constant in libhb.
+NSString *HBCoreWorkDoneNotification = @"HBCoreWorkDoneNotification";
+
+/// Notification sent to update status while muxing. Matches HB_STATE_MUXING constant in libhb.
+NSString *HBCoreMuxingNotification = @"HBCoreMuxingNotification";
+
+/**
+ * Private methods of HBCore.
+ */
+@interface HBCore (Private)
+- (NSString *)stateAsString:(int)stateValue;
+@end
+
+@implementation HBCore
+
+/**
+ * Initializes HBCore.
+ */
+- (id)init
+{
+    if (self = [super init])
+    {
+        state = HBStateIdle;    
+        hb_state = malloc(sizeof(struct hb_state_s));   
+    }
+    return self;
+}
+
+/**
+ * Releases resources.
+ */
+- (void)dealloc
+{
+    free(hb_state);    
+    [super dealloc];
+}
+
+/**
+ * Opens low level HandBrake library. This should be called once before other
+ * functions HBCore are used.
+ *
+ * @param debugMode         If set to YES, libhb will print verbose debug output.
+ * @param checkForUpdates   If set to YES, libhb checks for updated versions.
+ *
+ * @return YES if libhb was opened, NO if there was an error.
+ */
+- (BOOL)openInDebugMode:(BOOL)debugMode checkForUpdates:(BOOL)checkForUpdates;
+{
+    NSAssert(!hb_handle, @"[HBCore openInDebugMode:checkForUpdates:] libhb is already open");
+    if (hb_handle)
+        return NO;
+
+    state = HBStateIdle;    
+
+    hb_handle = hb_init(debugMode ? HB_DEBUG_ALL : HB_DEBUG_NONE, checkForUpdates);
+    if (!hb_handle)
+        return NO;
+
+    updateTimer = [[NSTimer scheduledTimerWithTimeInterval:0.2
+                                                    target:self
+                                                  selector:@selector(stateUpdateTimer:) 
+                                                  userInfo:NULL 
+                                                   repeats:YES] retain];
+
+    [[NSRunLoop currentRunLoop] addTimer:updateTimer forMode:NSModalPanelRunLoopMode];        
+    return YES;
+}
+
+/**
+ * Closes low level HandBrake library and releases resources.
+ *
+ * @return YES if libhb was closed successfully, NO if there was an error.
+ */
+- (BOOL)close
+{
+    NSAssert(hb_handle, @"[HBCore close] libhb is not open");
+    if (!hb_handle)
+        return NO;
+
+    [updateTimer invalidate];
+    [updateTimer release];
+    updateTimer = nil;
+    hb_close(&hb_handle);
+    hb_handle = NULL;
+    return YES;
+}
+
+/**
+ * Returns libhb handle used by this HBCore instance.
+ */ 
+- (struct hb_handle_s *)hb_handle
+{
+    return hb_handle;
+}
+
+/**
+ * Returns current state of HBCore.
+ *
+ * @return One of the HBState* string constants.
+ */
+- (const NSString *)state
+{
+    return state;
+}
+
+/**
+ * Returns latest hb_state_s information struct returned by libhb.
+ *
+ * @return Pointer to a hb_state_s struct containing state information of libhb.
+ */
+- (const struct hb_state_s *)hb_state
+{
+    return hb_state;
+}
+
+@end 
+
+@implementation HBCore (Private)
+
+/**
+ * Transforms a libhb state constant to a matching HBCore state constant.
+ */
+- (const NSString *)stateAsString:(int)stateValue
+{
+    switch (stateValue)
+    {
+        case HB_STATE_IDLE:
+            return HBStateIdle;        
+        case HB_STATE_SCANNING:
+            return HBStateScanning;
+        case HB_STATE_SCANDONE:
+            return HBStateScanDone;
+        case HB_STATE_WORKING:
+            return HBStateWorking;
+        case HB_STATE_PAUSED:
+            return HBStatePaused;
+        case HB_STATE_WORKDONE:
+            return HBStateWorkDone;
+        case HB_STATE_MUXING:
+            return HBStateMuxing;        
+        default:
+            NSAssert1(NO, @"[HBCore stateAsString:] unknown state %d", stateValue);
+            return nil;
+    }
+}
+
+/**
+ * This method polls libhb continuously for state changes and processes them.
+ * Additional processing for each state is performed in methods that start
+ * with 'handle' (e.g. handleHBStateScanning).
+ */
+- (void)stateUpdateTimer:(NSTimer *)timer
+{
+    if (!hb_handle)
+    {
+        // Libhb is not open so we cannot do anything.
+        return;
+    }
+
+    hb_get_state(hb_handle, hb_state);
+
+    if (hb_state->state == HB_STATE_IDLE)
+    {
+        // Libhb reported HB_STATE_IDLE, so nothing interesting has happened.
+        return;
+    }
+
+    // Update HBCore state to reflect the current state of libhb
+    NSString *newState = [self stateAsString:hb_state->state];
+    if (newState != state)
+    {
+        [self willChangeValueForKey:@"state"];
+        state = newState;
+        [self didChangeValueForKey:@"state"];
+    }
+
+    // Determine name of the method that does further processing for this state
+    // and call it. 
+    SEL sel = NSSelectorFromString([NSString stringWithFormat:@"handle%@", state]);
+    if ([self respondsToSelector:sel])
+        [self performSelector:sel];
+}
+
+/**
+ * Processes HBStateScanning state information. Current implementation just
+ * sends HBCoreScanningNotification.
+ */
+- (void)handleHBStateScanning
+{
+    [[NSNotificationCenter defaultCenter] postNotificationName:HBCoreScanningNotification object:self];    
+}
+
+/**
+ * Processes HBStateScanDone state information. Current implementation just
+ * sends HBCoreScanDoneNotification.
+ */
+- (void)handleHBStateScanDone
+{
+    [[NSNotificationCenter defaultCenter] postNotificationName:HBCoreScanDoneNotification object:self];    
+}
+
+/**
+ * Processes HBStateWorking state information. Current implementation just
+ * sends HBCoreWorkingNotification.
+ */
+- (void)handleHBStateWorking
+{
+    [[NSNotificationCenter defaultCenter] postNotificationName:HBCoreWorkingNotification object:self];    
+}
+
+/**
+ * Processes HBStatePaused state information. Current implementation just
+ * sends HBCorePausedNotification.
+ */
+- (void)handleHBStatePaused
+{
+    [[NSNotificationCenter defaultCenter] postNotificationName:HBCorePausedNotification object:self];    
+}
+
+/**
+ * Processes HBStateWorkDone state information. Current implementation just
+ * sends HBCoreWorkDoneNotification.
+ */
+- (void)handleHBStateWorkDone
+{
+    [[NSNotificationCenter defaultCenter] postNotificationName:HBCoreWorkDoneNotification object:self];    
+}
+
+/**
+ * Processes HBStateMuxing state information. Current implementation just
+ * sends HBCoreMuxingNotification.
+ */
+- (void)handleHBStateMuxing
+{
+    [[NSNotificationCenter defaultCenter] postNotificationName:HBCoreMuxingNotification object:self];    
+}
+
+@end